Business Secretary and MP for Twickenham Vince Cable said changes to the Liberal Democrat team in the run up to May’s general election will have no effect on his role.

Lib Dem leader Nick Clegg confirmed on Wednesday that Danny Alexander, currently chief secretary to the Treasury, would speak for the party regarding Treasury issues during the election campaign.

Mr Alexander will likely join Chancellor for the Exchequer George Osborne and shadow chancellor Ed Balls in televised debates leading up to the election, but Dr Cable, minister for business, innovation and skills since 2010, said the team selection would not mean any change to his own role, despite media coverage to the contrary.

He said: "It doesn’t affect me, I am still the economic spokesman. Effectively, Danny Alexander speaks for the Treasury and I speak for broader economic policy."

Edward Davey, MP for Kingston and Surbiton, recently revealed he would consider standing for leadership once Mr Clegg stands down, but Dr Cable said it wasn’t the time to be discussing whether he would also like the job.

He said: "There isn’t a leadership issue so I am not getting involved in that debate. It’s a job I have done before so it’s not a novelty, and I wouldn’t like to say either way."

Dr Cable, who retained his seat with a 54.4 per cent majority in 2010, said despite the Conservatives targeting Twickenham he was optimistic about winning once again.

He said: "I am optimistic as far as my own seat is concerned. We have done a lot of door knocking and feedback has been encouraging. The Conservatives are throwing a lot of money at our seat. We are not taking anything granted but I am optimistic.

"Across the country our poll ratings aren’t as good as they could be, but where we are strong, we are strong."