Andrew Goodfellow is Vice President of UK Policy Group, a research and political intelligence consultancy. He was the Conservative Party’s Director of Policy and Research from 2015 to 2017.

At the weekend, the Dailt Telegraph reported with barely concealed relish that the expected Conservative Party leadership contest would be ‘the dirtiest for a generation’. Christopher Hope’s impeccably sourced piece claimed:

‘And given the wide open nature of the field, it is hardly a surprise the teams are drawing up “war books” about one another according to one adviser, shining a light on controversial historic articles, details of alleged sexual peccadilloes and unsavoury claims about their partners.

One adviser said that “without a doubt” the campaigning in the upcoming Tory leadership campaign will be the dirtiest for decades. “The biggest feature in Westminster is people looking for dirt on other people. They are all at it [war books]. Everyone is going on about the war books, who has got what. It is already quite a nasty campaign.”’

Now, I love a good opposition research book more than anyone. A well-constructed dossier of votes, quotes, dodgy connections, questionable decisions and all the rest is, if done well, a thing of beauty.

I’ve been working in this field in one capacity or another for over six years, and opposition research is one of the most maligned and least appreciated elements of politics.

But I think any prospective Conservative leadership candidate commissioning this sort of work on their rivals is being badly advised, and making a tactical error.

Here are five reasons why:

You need to know your own weaknesses better than those of your opponents.

The last Conservative leadership contest ended with Andrea Leadsom giving an ill-advised interview, but even before that she was dogged by questions about inconsistencies on her CV. If her campaign had conducted proper due diligence and self-vetting work, they would have been prepared for the inevitable challenges that appeared in the press.

The level of scrutiny potential leaders or Prime Ministers face is huge – from the press and from political opponents. Concentrate your limited time and resources on ensuring that you are prepared to respond to anticipated attacks and shut them down comprehensively.

Avoid rows about process and tactics.

If your team get caught briefing against rivals, pitching opposition research stories to journalists, or starting whispering campaigns in the tea room, it will get out. There’s only a limited amount of space available to get your message out there- don’t let your campaign get embroiled in a row about who-said-what-about-whom.

Party management. These are your future Cabinet colleagues.

British political history is littered with examples of internal rows in the government sabotaging Prime Ministers. As a point of good politics, why would you deliberately antagonise your rival leadership candidates, when it’s highly likely that you’ll be sitting across the Cabinet table from them if you win?

Conservative MPs and members are crying out for some positivity.

The last three years of British politics have been thoroughly miserable. Doom, gloom, dire warnings, online abuse and fury, from all sides of politics.

Regardless of where they stand on Brexit, Conservative members want to know what a potential leader has to say about how they’ll bring the country together, and give us a vision of some sunlit uplands.

At the next General Election – whenever it comes – Labour will present an expensive package of spending pledges, cash handouts, and carefully targeted taxes.

The next Conservative leader would be wise to pitch to MPs and members with a set of policy proposals that will prove more appealing to the country than the Labour alternative.

Focus on the real enemy, don’t do Labour’s work for them.

Jeremy Corbyn and the Labour Party – now there’s a group of people who know a thing or two about internal disputes. They’re not going to sit on their hands and watch a Conservative leadership election unfold without making the most of the opportunity to inflict further damage.

Bright researchers at Labour HQ will be paging through microfilm of student newspapers, scouring YouTube for barely watched videos of obscure think-tank events, and assembling comprehensive documents of embarrassing quotes and controversial donations.

If you’re a Conservative, why on earth would you want to assist this process? Adding more opposition research into the political bloodstream will only give Labour and their allies more ammunition to aim at our party.

In his early days as leader of the Conservative Party, David Cameron urged members to “let sunshine win the day’” as he called for “optimism to beat pessimism”. The Grand National sized field of prospective Conservative leaders could do well to revisit that speech from the 2006 Party conference.

They need to make the most compelling possible pitch for why they are the best person to lead the party, not simply the ‘least worst’ option.

So rather than building opposition research dossiers on opponents, candidates should spend that time getting to know their own vulnerabilities, and mitigating against them.

Then they should put together the positive case for why they should lead our party and our country.

At the end of the day, the only winner from a messy Conservative leadership election would be Jeremy Corbyn.