If the Labour Party had more MPs like Simon Danczuk, the Conservatives would have scant chance of winning the next general election. While writing this profile, I kept coming across articles and speeches in which he argues the need for Labour to promote small business and self-reliance: as in this clip of him debating against the ineffably irritating Owen Jones.

But Danczuk, first elected as MP for Rochdale in 2010, has instead sprung to prominence as one of the few MPs prepared to ask why child sex abuse committed by public figures has for many years been covered up. This role was thrust upon him by his discovery that one of his predecessors in Rochdale, Cyril Smith – who captured the seat for the Liberals in a by-election in 1972, stood down undefeated in 1992 and only died in 2010 – was a brutal and prolific abuser of boys.

Some politicians who found themselves in this position would have done the minimum, uttering condemnations of their predecessor without getting to grips with the details of what he did. Danczuk, together with Matthew Baker, has instead written a book on the subject, Smile for the Camera – The Double Life of Cyril Smith, published earlier this year by Biteback.

The subject matter is so vile, and the literary merit of the work so slight, that I would not have got hold of a copy were I not writing this piece. But I am glad to have read it, for this account makes it impossible to dismiss the whole paedophilia story as an instance of the media at its most disreputable, inciting popular hysteria and a lynch-mob mentality on the basis of no firm evidence.

In Smith’s case, the evidence is clear. Danczuk quotes some of his victims. Their harrowing stories show that Smith did terrible things which inflicted lifelong damage on boys he had already identified as vulnerable.

The first case of which the police had knowledge dated from 1961. In March 1970 the police sent an “extremely forthright” 80-page report about Smith to the Director of Public Prosecutions. A week later, this was returned with a note recommending that no further action be taken. Three months later Smith, who since the 1950s had been a domineering figure in Rochdale politics and was a governor of 29 local schools, stood as the Liberal candidate in the general election of 1970.

The book includes material favourable to Smith. It describes his brilliance as an electioneer: when he won Rochdale in 1972, it was the first northern industrial town which the Liberals, driven back to the Celtic fringes of Britain, managed to win. The party was rich in well-to-do Oxbridge types: it possessed no one else like Smith, an authentic member of the working class from a desperately deprived background, with an extravagant gift for street politics, able to make an emotional connection with voters, to cheer them up by making jokes and to run successfully on the slogan “Vote Smith the man”. He was the fattest person ever elected to the House of Commons, and for a time one of the best known.

So why did Smith get away with his child abuse for so long? Why, seemingly, was so much effort put into protecting him?

Smith had huge local influence, which he naturally used to protect himself. He was very good at making people feel under an obligation to him. And during most of his 50 years as a considerable figure, there was very little inclination on the part of those in authority to expose child abuse, or even to believe it could be going on in any serious way. Nor did the Liberals reckon, after the Jeremy Thorpe affair, that they could take another sex scandal. They still don’t.

One of the strengths of Danczuk’s account is that he does not pretend to have anything like a full explanation of why things went so wrong. He does, however, remind us of the refusal of the authorities to regard the testimony of working-class boys from broken homes as in any way reliable. The same problem has more recently arisen with working-class girls in Rochdale. As Danczuk writes, “They were invisible people whose voices were not supposed to be heard.”

He considers that part of his duty as a Labour MP is to speak for these neglected members of the working class who find the Establishment has turned a deaf ear. It is not surprising he opposes the appointment of Lady Butler-Sloss to chair the inquiry into child sex abuse. As he told the Sun: “This gives the impression that it’s going to be the Establishment investigating the Establishment.” Danczuk went on: “It’s vital now that we have non-Establishment figures on the rest of the panel — and preferably a ‘survivor’ of child abuse.”

I am not sure I agree with Danczuk about this: in my opinion, in order to overcome the deeply rooted refusal of some members of the Establishment to admit to past errors, such as the conviction of the wrong people for the IRA pub bombings, it is generally necessary to recruit and deploy other members of the Establishment.

But it is hard to deny his contention, reiterated a few days ago in the Mail on Sunday, that many of our most senior politicians simply do not want to know about child abuse. He began that article with an anecdote so striking it was widely reported in other newspapers, but here it is in Danczuk’s own words:

“As I was I was making my way from the House of Commons on Monday night after a late vote a Tory minister stepped out of the shadows to confront me. I’d never spoken to him before in my life but he blocked my way and ushered me to one side. He warned me to think very carefully about what I was going to say the next day before the Home Affairs Select Committee when I’d be answering questions on child abuse. ‘I hear you’re about to challenge Lord Brittan about what he knew about child sex abuse,’ he said. It wouldn’t be a wise move, he advised me. ‘It was all put to bed a long time ago.’ He warned me I could even be responsible for his death. We looked at each other in silence for a second. I knew straight away he wasn’t telling me this out of concern for the man’s welfare.”

Towards the end of the same piece he wrote:

“A few months ago police officers came to visit me to discuss an investigation into a current parliamentarian accused of horrific child abuse. I listened to some of the details of the alleged crimes and my stomach churned. Did I think it was likely that their inquiries would be met by political interference, the police asked? I looked at them in utter disbelief. How can the police put a Cabinet Minister behind bars for lying about speeding points but be worried they couldn’t properly investigate someone for child abuse? The incident spoke volumes about the mindset that pervades politics. This kind of obstructive, ‘Look the other way, sweep it under the carpet’ thinking threatens to drag politics to new depths of public hate.”

Lord Tebbit confirmed on last Sunday’s Andrew Marr Show that in the 1980s it was considered “more important to protect the system than to delve too far” into allegations of child abuse. He added that this attitude was wrong then and is now “spectacularly shown to have been wrong”.

I agree there is a danger of a witch hunt, and of horrible rumours being treated as facts, when they are no more than malicious inventions which have taken on a life of their own. But this is another argument for going as fully and accurately as possible into the whole subject.

Where does Danczuk’s toughness come from? His demeanour is that that of a Pole who is resolved not to give in. He was born in October 1966 in Hopton in Lancashire, and is one of only five MPs of Polish descent to have sat in the Commons since 1945 (the others are Stefan Terlezki, Denis MacShane, Mark Lazarowicz and Daniel Kawczynski). After a memorial service held in Rochdale to commemorate the victims of the famine inflicted by Stalin on the Ukraine in 1932-33, Danczuk said: “It was a poignant occasion which I won’t forget in a long time. Over the years my family have had strong connections with the Ukraine and it’s where my name originates – that gives the occasion special significance for me.”

Danczuk left school at the age of 16 and went to work in a factory which made gas fires. In his maiden speech in the Commons he recalled:

“I, like many other people, was brought up on free school meals in a one-parent family helped by the welfare state. It was hardly surprising that I left school with no qualifications and little confidence to get on in life, but it was the availability of further education and the support of my trade union that combined to create a second chance for me.”

He studied at night school, read economic sociology and politics at Lancaster University, and founded a research company with Ruth Turner, who now works for Tony Blair. After a period of success, this company lost most of its business after the 2010 general election and went into liquidation with debts of £222,000.

At the same time, Danczuk became heavily involved in Labour politics in Lancashire, serving as a councillor for eight years in Blackburn, and as an election agent. He was selected in 2007 as Labour’s candidate to fight Rochdale, but fell out badly with some people on his own side. As he wrote in a recent piece for the Huffington Post:

“It’s not easy getting elected to Parliament. It takes a lot of time, involves huge sacrifices and can be particularly unpleasant. In my case I received death threats – I had a three-foot funeral wreath sent to my office and was told if I didn’t withdraw from the parliamentary selection process my body parts would be found spread across the M62 motorway. Then there was a three-year battle with the Liberal Democrats, an exhausting campaign that involved knocking on thousands of doors and the debacle with Gordon Brown turning up just before the election and calling my constituent Gillian Duffy a bigot. But as perilous as my journey – and that of many other candidates – was to become an MP, it’s nothing compared to the struggle faced everyday by thousands and thousands of people running small businesses. As someone who’s had experience of both – I co-founded a research and communications agency – I’m left in no doubt: running a small business is a lot harder than becoming a politician.”

In December 2013, he and his second wife, Karen, set up a new business in Rochdale, Danczuk’s Delicatessen. His entrepreneurial instincts and experience make him unusual among MPs, especially on the Labour benches. Earlier this month, when he gave evidence on child sex abuse to the Home Affairs Committee, Danczuk remarked in passing that his real specialities are regeneration, the high street and the reform of business rates.

He hardly ever votes against his party, but expresses very strong views about how it should be run. In July 2013 he wrote a tremendous piece for the Daily Telegraph which began:

“It’s not just David Cameron that has problems with swivel-eyed loons. Unfortunately, they’re in every political party and there’s no point suggesting otherwise. Ed Miliband has made it very clear that he’s placing our party firmly in the centre ground, but there’s a growing number of militant malcontents busting a gut to pull him towards a no-man’s land on the far left. The fallout from the Falkirk imbroglio has brought many things out into the open. And attempts by people on the hard left to explain it away just won’t wash. Some young lefties say the Falkirk stitch up was necessary to get more working class MPs into the party. This is nonsense. What they really mean is getting into politics people with the same views as them.”

Danczuk protested that if, like him, you stood up to the Left, you were immediately labelled a Tory, or worse still a Blairite. I would not wish to make him more vulnerable to such attacks by hailing him as a fellow Tory. It seems clear to me that he is a socialist, who believes that his task is to stand up for and give a voice to the shattered remnants of the working class, but to do so in a tough-minded way. On subjects like welfare reform, he resists the temptation to defend the status quo, and is far bolder than Miliband in calling for reform. He is also scathing about his party’s record on immigration, as in this interview with Total Politics, published earlier this year:

“The Labour government were far too relaxed in terms of immigration…Gordon Brown got it completely wrong during that last general election. Door-knocking before I was an MP, every fifth door would mention immigration, yet Brown failed to provide any leadership… He ignored them instead. That certainly affected the result of the election.”

It is easier to profile oneself as an independent-minded MP, than to attract any kind of attention by repeating the official party line. But Danczuk’s way of doing things also requires more courage. By adopting such clear positions, he lays himself open to attack, and those opponents who can see no way of defeating his arguments instead try to go for him as a person.

It was noticeable that at this week’s Prime Minister’s Questions, Miliband generally backed Cameron’s approach to the child sex abuse scandal.

Danczuk makes Miliband look timid: the Labour leader has a tendency, when things get difficult, to side with the Establishment rather than to question it. As I suggested at the start of this article, if Labour had more people like Danczuk, it would present a more dangerous threat to the Tories.