Jo Swinson wants to be Lib Dem leader

East Dunbartonshire MP Jo Swinson says she will lead a movement to tackle "nationalism and populism'' after confirming she will stand for the Liberal Democrat leadership.

The party's deputy leader said she was the right person to lead the "liberal movement'' as she entered the contest to succeed Sir Vince Cable.

The leadership contest comes as the Lib Dems received an opinion poll boost, with a YouGov study suggesting they are the most popular party.

A new Lib Dem leader will be in place on July 23 after Sir Vince announced his decision to stand down earlier this year, and Ms Swinson will face competition from former cabinet minister Sir Ed Davey.

Ms Swinson, who also served as a minister in the coalition government, will officially launch her campaign on Friday but is already the bookmakers' favourite.

The party came second in the European elections and the YouGov poll for The Times suggested its popularity has increased even further.

The Lib Dems were on 24%, ahead of the Brexit Party on 22% and the Tories and Labour neck and neck on 19%.

It is the first time the Lib Dems have been in the top spot in a question on how people will vote in a general election since the heady days of Nick Clegg's popularity in 2010.

But YouGov's Chris Curtis cautioned against the Lib Dems getting too carried away with the bounce they have enjoyed since the European elections.

He said: "The Cleggmania of 2010 faded fast, with the party falling back in the final weeks of the campaign and ending up with just 1% more of the vote than they had won five years prior.''

Ms Swinson's rival for the leadership launched his campaign with a plan to call on the Queen to stop a no-deal Brexit.

Sir Ed said he would propose a "cross-party humble address to Her Majesty, requiring the Prime Minister to revoke Article 50 if we got to the cliff edge.

"I hope Jeremy Corbyn will join me in that address.''

A humble address is a direct communication from the House of Commons to the Queen, calling on the Government to comply with a request.

If approved, humble addresses are considered to be binding on the House.

Sir Ed, the party's home affairs spokesman, said: "Under my leadership, the Lib Dems will continue to lead the fight to stop Brexit, nothing is more urgent in British politics today.''

• YouGov surveyed 1,736 British adults on May 28-29