Who will be the next leader of the Liberal Democrats?

Politics Explained: Unlike the crowded Tory contest, the Lib Dem competition is likely to be a two-horse race

As Conservative leadership hopefuls descend into rows over Brexit, taxation and opium smoking, the starting gun has been fired on another contest.

Sir Vince Cable announced plans to step down as Liberal Democrat leader on 23 July after two years, informing activists of his decision only hours after Theresa May made an emotional speech setting out the date of her own departure.

Unlike the crowded Tory contest, which will loom large over proceedings, the Lib Dem competition is likely to be a two-horse race.

Candidates have to secure the support of 10 per cent of the parliamentary party – effectively the backing of one MP – and then 200 members from at least 20 local parties.

Sir Ed Davey was first to declare, setting out his stall on Thursday with a pledge to block a no-deal Brexit and strong denouncements of Nigel Farage and Tory frontrunner Boris Johnson, whom he described as a “preacher of division”.

The former energy secretary intends to draw on his old brief with a plan to make “capitalism green” through systemic change in the City of London.

At his launch event in London, Davey called for 15 per cent of global fossil fuel investment to be switched into green technologies for the future.

He will face stiff competition from deputy leader Jo Swinson, the bookies’ favourite, who is expected to declare her candidacy within days.

Swinson, a former business minister, was seen a strong contender during the last contest in 2017 after the resignation of Tim Farron.

However the East Dunbartonshire MP, who entered parliament in 2005, decided to stand for the deputy leadership instead.

A vocal equality campaigner, Swinson has written a book on gender imbalances in the workplace and spoke out when the Tories broke pairing arrangements during a key Brexit vote while she was on maternity leave.

She also made history when she took her baby son into the Commons chamber.

One of the issues for both candidates is they are marked by the coalition years, which caused huge damage to the party’s electoral chances.

Education spokesperson Layla Moran dashed hopes of a fresh face in the contest when she ruled herself earlier this month.

After years in the wilderness over their involvement in the coalition years, the party has hailed a resurgence in support in the recent European and local elections.

However, the main challenge for both candidates will be to stake a claim to what the Liberal Democrats stand for, beyond Brexit.