Eastleigh by-election: Maria Hutchings to stand for Conservatives
The Conservatives have announced their candidate for the Eastleigh by-election will be Maria Hutchings, who finished second behind Chris Huhne in the 2010 general election.
Party chairman Grant Shapps described Mrs Hutchings as someone "people in Eastleigh can trust".
Mr Huhne quit on Tuesday as MP for the Hampshire seat after pleading guilty to perverting the course of justice.
The Lib Dems have said the campaign should not be based on "retribution".
The vote is due to take place on 28 February. The Lib Dems held the seat with a 3,864-vote majority in 2010.
Mr Shapps said: "Maria Hutchings will be a brilliant local MP that people in Eastleigh can trust. She is already working hard for local people and is in tune with the community."
"I'm looking forward to joining her on the doorstep."'Snatched'
Mr Clegg said: "What has happened has happened with Chris Huhne and his guilty plea.
"I think the choice for the people of Eastleigh in the by-election is what kind of an MP do they want to have now. I hope that it will be on that basis, rather than in a mood or spirit of retribution, that the debate will be conducted in Eastleigh."
Earlier, in a speech, he highlighted divisions in the coalition over the Lib Dems' proposals for higher taxes on the most valuable properties - a policy the Conservatives oppose.
But Labour deputy leader Harriet Harman said: "Nick Clegg can talk about his differences with the Tories as much as he likes - the issue is what he does.
"Nick Clegg's actions in backing a Tory-led government tell a truth his speeches try to hide."
In 2005, Mrs Hutchings challenged then Prime Minister Tony Blair during a live TV debate over the proposed closure of a special school.
The former Labour supporter showed Mr Blair a photo of her autistic son, explaining that she was struggling to get the speech and language therapy he needed.
She told the BBC in 2006 that the Conservatives had "snatched the social justice agenda from under the Labour Party's feet".
No other parties have yet announced who their candidates will be, although UKIP leader Nigel Farage has said he will not be standing.