The former Lib Dem MP for Solihull who lost her seat in May's General Election has vowed to help the party become a major force again in British politics after being appointed its business spokesperson, according to new leader Tim Farron.

Mr Farron, who won the Lib Dem leadership election earlier this month, praised Lorely Burt who lost her seat to Conservative candidate Julian Knight.

An MP since 2005, Ms Burt has now been appointed the party's spokesperson for business, innovation and skills, shadowing Business Secretary Sajid Javid, the Conservative MP for Bromsgrove.

A role like this would usually go to an MP but Mr Farron has been forced to add members of the House of Lords and people such as Ms Burt, who have left Parliament entirely, to his senior team after the party won only eight Commons seats in May.

Mr Farron said: "Lorely has a great understanding of the needs of business and she will play a major part in the party's fightback."

He said his team "features some of the best campaigners the party has, balanced with the experience and economic credibility our party has developed over the last five years in government".

She said: "Britain needs more than one pro-business party and the Conservatives must be challenged and held to account.

"Many changes they plan to introduce will damage prospects for business growth and jobs - the Lib Dems will ensure that challenge is met."

Ms Burt is a former chair of the Liberal Democrat Parliamentary Party and was a whip in the Conservative and Lib Dem Coalition Government.

The result of the May 7 General Election was a disaster for the Liberal Democrats which won 57 seats in 2010.

With eight seats, they are now the joint fourth largest party - tied with the Democratic Unionist Party, the Northern Irish party founded by the late Ian Paisley.

Their traditional role as the third party has been taken by the Scottish National Party (SNP) which won 56 seats.

It means SNP spokespeople - rather than Lib Dems - are now guaranteed the chance to question government ministers.

Baroness Kramer, a member of the Lords, will speak on economic matters, a post offered to former leader Nick Clegg who turned it down.