Image copyright PA Image caption Sir Vince said only the Lib Dems had a "consistent and principled" stance on Europe

Sir Vince Cable says he is a candidate to become Liberal Democrat leader.

The former business secretary, who has served as deputy leader and acting leader in the past, is throwing his hat into the ring after Tim Farron said he would stand down this summer.

Sir Vince, 74, has been a senior figure in the party for over 20 years and won his Twickenham seat back at the election.

Another ex-minister, Jo Swinson, has become deputy leader.

Ms Swinson, who had been tipped for the top job but ruled herself out last week, was elected unopposed as deputy after the deadline for applications passed at 17:00 BST.

Other possible leadership candidates include ex-ministers Norman Lamb and Sir Ed Davey.

Announcing his candidacy on the Lib Dem Voice website, Sir Vince said the "political winds" were moving in the party's direction and it could become a "credible contender" for power, with the Conservatives "in disarray" and Labour still lacking economic credibility.

"There is a big space in British politics which I am determined that we should occupy," he wrote.

"I am ready to commit my energy, enthusiasm and experience to the task of leading the Liberal Democrats through what will be a period of chronic uncertainty. With the prospect of another election looming large, we must be ready for the fight."

'Up for contest'

The BBC's assistant political editor Norman Smith said Sir Vince, currently the party's economic spokesman, is likely to stress his economic background and his ministerial experience after five years serving in the coalition government.

Sir Vince has said he will continue with the Lib Dems' call for a fresh referendum on any Brexit deal.

He told Lib Dem Voice. "We must fight for the British public to have a final say on the government's deal with a chance to stay in the EU if the deal is not good enough. To achieve this, we will need to work with like-minded people in other parties."

Sir Vince started his political career as a Labour councillor in the 1970s before defecting to the SDP and subsequently joining the Lib Dems. He served as deputy leader between 2006 and 2010 and as acting leader for several months after Menzies Campbell's resignation in 2007.

Lord Campbell, who was 66 at the time, cited his age as one of the reasons for standing down. But Sir Vince told BBC Radio 5 Live that experience was a virtue, pointing out that William Gladstone had become prime minister for the last time when he was 82.

"Some of the brightest and most interesting people in British politics recently have been relatively old," he told the Adrian Chiles show. "You remember Bernie Sanders in America as well... I don't feel old, I feel young and energetic and I'm very much up for a contest."

Sir Ed Davey, who also won his seat back after being defeated in 2015, said he would be announcing his intentions later this week. He told the BBC that a "lot of people", including his wife, had been encouraging him to run.

The party is looking for a new leader after Mr Farron said he could no longer reconcile his Christian faith with his responsibilities as leader of a progressive political party. The Lib Dems won 12 seats at the general election, four more than in 2015, but its vote share actually fell to 7.3%.