David Cameron and Ed Miliband should refuse to meet David Laws, Nick Clegg's nominee to lead all-party talks on political party funding, a Labour MP has said.

Backbencher John Mann has written to the prime minister and Labour leader demanding the refuse to take part in the negotiations given the Yeovil MP's "disgrace" over his expenses claim.

Laws, a close ally of the deputy prime minister, resigned as chief secretary to the Treasury in the early days of the coalition after he was found to have abused his parliamentary expenses.

In May last year he apologised "without reservation" for his error.

It is widely believed that both the Lib Dem leader and David Cameron would like to see him return to front line politics, but do not yet feel he can be brought back into the cabinet given his resignation over such a toxic issue.

But on Sunday the Independent reported that Laws had been given a role by Clegg, to lead talks on reforming the way political parties are funded.

Last week the Guardian reported that Clegg had written to Cameron and Miliband, in his role as minister responsible for constitutional affairs rather than as Lib Dem leader, to ask them to nominate two people to represent the Conservative Party and Labour in the talks.

"In my view David Laws is not fit to be an MP," Mann said. "But it is the voters, not me who must have the final say."

"It is fundamental to our democracy that David Laws faces the electorate for their verdict before being rehabilitated. This has not yet happened and until it is then Laws is unacceptable in roles such as this," he said.

"If David Laws can persuade the electorate then he would be free to be offered and to accept any position, but not until the people have they say."