Labour’s position on Brexit is notoriously indistinct, but Barry Gardiner can reduce it within seconds to a pile of smoking rubble. The shadow Trade Secretary is one of the most remarkable figures to rise to prominence during Jeremy Corbyn’s leadership.

As one insider puts it, “Gardiner was so useless on Marr, Newsnight etc and couldn’t stick to the line at all, to the point that the Leader’s office actually started asking Tom Watson to do it again”.

Nothing in Gardiner’s record indicates he has ever been even a closet Corbynista. Yet when Corbyn’s enemies attempted in the summer of 2016 to defenestrate the Labour leader by resigning en masse from the shadow Cabinet, Gardiner, with characteristic independence of mind, swam in the opposite direction, and accepted the trade portfolio.

Only in a period when party discipline has often broken down could he have retained this post for the best part of three years, during which Gardiner has repeatedly exploded the careful compromises crafted by his colleague Keir Starmer, the shadow Brexit Secretary.

On one celebrated occasion, he was recorded at a think tank in Brussels dismissing the six tests Labour said it was going to apply to whatever Brexit deal the Government managed to negotiate:

“Well let’s just take one test – the exact same benefits. Bollocks.

“Always has been bollocks and it remains it.

“We know very well that we cannot have the exact same benefits and actually it would have made sense – because it was the Tories that said they were going to secure the exact same benefits – and our position should have been to say they have said they are going to secure the exact same benefits and we are going to hold them to that standard.”

Gardiner has the unhappy knack of sounding as if he is congratulating himself on being extremely intelligent and always knowing best. A smile plays about his lips as he steers his craft through the reefs and shoals of Brexit.

When Emma Barnett challenged him about the glaring contradictions between his own views and the party’s official position, he replied:

“If all you ever do is stick by the given line you’d never actually advance it, because you’d never discuss anything with people. But that’s the reason for holding things in private…”

Gardiner’s suggestion that he only makes controversial contributions in private is nonsense. He used an article in The Guardian to rubbish the idea that the UK should stay in the customs union, or in the European Economic Area. Under the latter proposal, he pointed out,

“The UK would technically not be a member of the EU, but we would in effect become a vassal state: obliged to pay into the union’s budget while having even less sovereignty than we do now – no longer able to appoint commissioners, sit on the EU council to have a say in how we determine our regulations and laws, or appoint British judges to the ECJ to adjudicate disputes. The 52 per cent would almost certainly consider this a con.”

If asked to guess who coined the term “vassal state” in the Brexit context, many people would say Jacob Rees-Mogg, but it was actually Gardiner. The Shadow Trade Secretary proceeded to insist there is a distinction between “the customs union” (which he opposes) and “a customs union” (which Labour favours).

His whole history is full of implausible distinctions and surprising moments. His father, Jackie Gardiner, played football for Great Britain at the 1936 Olympics.

Britain were beaten 5-4 by Poland in the quarter finals. The Guardian reported that “Gardiner annoyed the crowd by his hefty charging and there was some booing when he bowled over God.” The opponent in question was actually the Polish forward, Hubert Gad.

Barry Gardiner will be 62 next Sunday. He was brought up in Glasgow, where his father, who had played for Queen’s Park, ran the Kelvin Hall exhibition centre, while his mother, a doctor, was the first woman to win the gold medal for surgery at Glasgow University.

He was educated at Glasgow High School, the only day school to have educated two Prime Ministers (Henry Campbell-Bannerman and Andrew Bonar Law), and at Haileybury (attended by and looked back on with affection by Clement Attlee).

Perhaps those institutions helped instil the air of self-confidence which is so marked a feature of Gardiner. He read Moral Philosophy at St Andrews, intended for a time to enter the priesthood, and spent two years as Scottish Regional Secretary of the Student Christian Movement.

But instead he went on a Kennedy scholarship to Harvard, followed by research at Corpus Christi College, Cambridge, where he was also elected a Labour councillor and became the city’s youngest ever Mayor.

For some years he earned his living by working as a marine arbitrator. In Labour’s great general election victory of 1997 he defeated Rhodes Boyson in Brent North, a seat which might more comprehensibly be called Wembley, now held by him with a majority of 17,000.

in memoirs of the Blair era, Gardiner’s name seldom figures. Matthew Parris offers us a glimpse of him in 2001:

“Speaking for the unctuous, Barry Gardiner has the syrupy voice, the beard and the ingratiating manner of the genie (‘your wish is my command’) in Aladdin.”

Gardiner served in various junior ministerial roles, striking people as very loyal to Blair and eager to rise higher, but when Gordon Brown took over in 2007 was only appointed “special representative on forestry”.

Dissatisfaction with this modest level of recognition may have played a part in his decision, a year later, to accuse Brown of

“vacillation, loss of international credibility and timorous political manoeuvres. The tragedy for those of us who nominated the Prime Minister is that since achieving power he appears to have forgotten what it was he once wanted to do with it.”

In 2010 Gardiner nominated David Miliband for the leadership. After Ed Miliband’s victory, Gardiner nevertheless became in due course a shadow environment minister, climate change being a threat he has long recognised.

But it is only since 2016, when he astonished people who still thought of him as a Blairite by joining Corbyn’s team, that Gardiner has emerged as a prominent Labour spokesman who enjoys trading blows with journalists when he thinks they have got things wrong.

He assured Patrick Maguire of The New Statesman that he has never belonged to any faction: “My loyalty is to the Labour Party. That probably accounts for why I’ve been so obscure for so long.”

Gardiner is no longer exactly obscure, but remains something of a loner, known for doing his own thing rather than for concerting his efforts with other MPs, and arousing a certain derision among some of his comrades: “I think he thinks he can be leader.”

On the other hand, no one ever thought Corbyn could be leader. But Corbyn always belonged to a gang, which Gardiner does not.

It is, as Anne Perkins noted in The Guardian in 2017, “almost impossible to predict what might come next” for the shadow Trade Secretary.

His wife, Caroline Smith, has long worked for him, and is herself an admirable poet. They have four children. In an online review of her volume Thistles of the Hesperides, Gardiner compared her to Seamus Heaney and Robert Browning, but unfortunately did so without declaring himself to be her husband.

Many people have watched with astonishment as Gardiner reinvented himself. The man is a performer, nimble, eager to please, seemingly unembarrassable. Brown, on being denounced by him, had reason to call him the inconstant Gardiner. What, one cannot help wonder, will Corbyn end up calling him?