North Norfolk MP Norman Lamb knows his first opponent in the Liberal Democrats' leadership race should he stand.

Former business secretary Sir Vince Cable has become the first contender to throw his hat into the ring to replace Tim Farron as the party's leader.

Mr Lamb is still undecided about whether he will run for the leadership of the Liberal Democrats.

Sir Vince, 74, returned to the House of Commons as MP for Twickenham in this month's General Election, having been one of the highest-profile casualties of the party's collapse in support in 2015.

Meanwhile, hotly tipped East Dunbartonshire MP Jo Swinson, 37, has ruled herself out of the race, saying she will fight for the deputy leadership instead.

Declaring his candidacy on the Lib Dem Voice website, Sir Vince said he is ready to 'work with like-minded people in other parties' to secure a second referendum on any Brexit deal, with the option to stay in the EU if the agreement on offer is not good enough.

He described Brexit as an 'iceberg' about to hit the UK economy and said the party should 'warn of the dangers ahead and the need for a new course'.

Despite the disappointment of the Liberal Democrats securing only 7.4pc of the vote and 12 seats in the election, Sir Vince insisted 'the political winds are moving in our favour'.

He said: 'There are big opportunities ahead. The Conservatives are in disarray and in retreat. The Labour Party outperformed expectations but complacently believes that 'one more heave' will see it into office.

'But an economic policy based on offering lots of free things lacks economic credibility and will be found out. Investing in infrastructure, rather than borrowing for everyday running costs is credible. There is a big space in British politics which I am determined that we should occupy.'

Sir Vince previously served as acting leader following the resignation of Sir Menzies Campbell in 2007, but declined to stand for the top job at that point.

If elected, he would be the party's oldest ever leader and the oldest leader of a major party since Sir Winston Churchill, who was 80 when he stepped down as Conservative leader.