Sam Gyimah, the former Conservative minister who defected to the Liberal Democrats at their party conference last month, has announced that he will be fighting the next general election, not in his East Surrey constituency, but in the key marginal of Kensington.

What are his chances? For many reasons, not least that the Liberal Democrats are unlikely to stand one of their new big-hitters in a seat where he is only going to lose, they look rather good.

Kensington has long been touted as the natural preserve of a moderate, pro-Remain Conservative-style candidate at the next general election. When Amber Rudd resigned the Conservative whip and announced she wouldn’t be standing again in Hastings and Rye, it was Kensington where she initially hinted she would be standing (she is now widely expected to run in neighbouring Chelsea and Fulham). Earlier in the year, when whispers abounded that George Osborne was to return to frontline politics, only one possible seat was mentioned: Kensington.

Now, Sam Gyimah is the candidate to tick those boxes: now a proud Liberal Democrat, his credentials are still those of a Conservative moderate, a Remainer and an Osborne/Cameron protégé (Gyimah was Cameron’s PPS, meaning he had the ear of the PM as his trusted go-between with the parliamentary party). So Sam’s the man, but can he win?

Previously considered a safe Conservative seat, Kensington produced the smallest margin in England in the 2017 election: Labour’s Emma Dent-Coad beat the Conservative incumbent, Victoria Borwick, by only 20 votes.

There are two defining features of Kensington: firstly, with a 68.9 per cent vote to Remain, it is one of the most pro-Remain constituencies in the country; it is, secondly, the most unequal constituency in the UK, contrasting millionaires and celebrities in South Kensington, Holland Park and Notting Hill with the deprived communities of North Kensington, where residents are still profoundly marked by the Grenfell fire.

Dent-Coad, herself a trail-blazer for exposing the inequality in her constituency, is well-liked by the more deprived communities in Kensington, who broadly feel that she has stood up for their interests and been their champion on local issues; in more affluent areas, the feeling in Dent-Coad’s team has been that she is trusted as a staunch Remainer by her constituents, regardless of the Labour leadership’s line: Brexit, they acknowledge, is the biggest issue on doorsteps. Before Gyimah announced his candidacy, Labour was campaigning furiously in the area, but didn’t expect much of a challenge from the Conservative candidate, Felicity Buchan, who is not, they emphasise, a Remainer.

But now that Gyimah is standing, he treads on Dent-Coad’s territory as the candidate to unite the Remain vote where she can’t. Where some in Kensington might have qualms over voting for Corbyn’s Labour, Gyimah’s appeal to Conservative Remainers is obvious, although it is unclear if his former Tory pedigree will put off Labour Remainers.

This is one seat where the campaign itself may have a big sway on voters: contests in Kensington have been deeply personal in the past, with a string of negative stories circulated about Dent-Coad by other candidates, and that was before Kensington was a hotly-contested marginal.

Both the Conservatives and Labour in Kensington are today emphasising that a vote for the Liberal Democrats will equal a victory for their main rival: “Vote Lib Dem get Tory!” is Dent-Coad’s simple message, while Buchan has been tweeting that “Only the Conservatives can beat Labour in Kensington.”

It is strongly in Labour and the Conservatives’ interests, of course, to frame Kensington as a two-way contest. And it is a credible threat: the Liberal Democrats did languish behind in a distant third in Kensington at the last General Election, and it is a leap of faith for a voter to back someone who isn’t in the top two in the last election.

But, if the Liberal Democrats’ boasts to the Evening Standard are to be believed, Kensington is already a two-way race, but between the Liberal Democrats and Labour. The challenge, as ever for the Liberal Democrats, will be to convince voters of that fact. It's going to be a fascinating race.