In life, the impossible question is, ‘What if?’. What if this or that had or hadn’t happened? British politics has been full of these ‘sliding door’ moments in the last 20 years. Liam Fitzpatrick gets out his crystal ball and looks at the alternative realities spanning Blair and Cameron’s premierships.

1. Blair says no to Iraq war

It might seem strange now, but at one stage, Tony Blair was one of Britain’s most popular ever Prime Ministers. In 2003 he was riding high after back-to-back landslide election wins and a long list of genuinely popular policy achievements.

But the devil in the ear of domestic Blair was foreign policy Blair, a demon with a god complex and belief he had a duty to ‘save the world’. In 1999 this had served him well in Kosovo, but four years later, he made the fateful decision to follow the USA into Iraq. We all know what happened next: Dodgy dossiers, WMDs and the reputational damage from which Blair would never truly recover.

But what if he had held firm and listened to his backbenchers and the public, choosing to stay out of the conflict in the Middle East?

Without invading Iraq, Blair likely remains a popular figure going into the 2005 election, which he again wins, winning acclaim for staying out of a messy war, including from the parties far left on his backbenches. With Blair remaining popular, he is able to continually frustrate Gordon Brown and avoid handing over power to him, with the Chancellor resigning in 2007. The 2010 election is a closer affair, but New Labour has its last hurrah, narrowly defeating David Cameron’s Conservatives. Cameron resigns, his vision for a more liberal, ‘one nation’ conservatism in tatters.

Blair stands down before the 2015 election and is given a knighthood, widely regarded as Britain’s best post-war PM. The Conservatives lurch to the right under the leadership of new opposition leader Boris Johnson. Johnson steps aside as London Mayor to wage war on Blair and his successor (David Miliband?). In the run-up to 2015’s poll, dangling an EU referendum as a carrot for voters considering returning the Tories to power. Who wins? Who knows.

2. referendum result reversal

It is the morning of June 24, 2016, and David Cameron is feeling relieved. Yes, it was closer than many had expected, with Remain only receiving 52% of the vote but ultimately, the PM’s gamble has paid off. As he says outside 10 Downing Street that morning, “The once-in-a-generation debate has been settled and now, we can come together as one United Kingdom together and stronger in Europe”.

Nigel Farage claims the result shows that the debate around Europe is far from over and vows to campaign for a second referendum, albeit from the sidelines.

Jeremy Corbyn is criticised by his party for a lukewarm campaign that allowed the result to be worryingly close, but his leadership faces no immediate threat.

Boris Johnson’s leadership ambitions are on ice for now, but he can console himself with a plum cabinet job, a peace offering from the Cameroons to the Brexiteer wing of the party.

For Cameron, the potential constitutional crisis of Brexit has been averted and politics can continue as normal. He’ll see out his five-year term and then hand over the reins. Maybe to George, Michael, or – heaven forbid – Boris.

The next election is miles away, 2020 in fact. Nothing will stop that election from happening…