Tories have been warned not to expect a direct boost in support from Chris Huhne's fall from grace as they unveiled their candidate for the Eastleigh by-election.
Maria Hutchings, who failed to topple Huhne in 2010, will fight the seat again after a guilty plea to dodging a speeding penalty ended the ex-cabinet minister's political career.
Conservative Party chairman Grant Shapps and Mrs Hutchings both spoke about "trust" ahead of a weekend blitz in what promises to be a brutal battle with their Liberal coalition partners. Deputy Prime Minister Nick Clegg had earlier urged voters not to exact retribution for his former leadership rival's disgrace.
But former Tory Treasurer Lord Ashcroft warned his party that though it started the contest in the lead, his polling suggested few voters were likely to "switch out of disgust". The survey conducted for the peer in the immediate wake of Huhne's resignation put the Tories on 34%, with Lib Dems on 31%, Labour on 19% and Ukip fourth with 13%.
Sources said the Tories were preparing a "big push" in the Hampshire town as local Lib Dems meet to select the party's candidate. It is defending a 3,864 majority.
Mr Clegg said: "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."
Labour sources are hoping for a strong showing, but privately accept they have little chances of winning despite being nine points up on their 2010 showing in the Ashcroft-commissioned poll. The figures represent a fall of almost 16 points in Lib Dem support since the 2010 general election, when Huhne scooped 46.5% of the vote.
Tories are down five points since the election and Labour and Ukip both up nine.
Lord Ashcroft, a major Tory donor who was deputy chairman of the party until 2010, said the poll suggested both coalition parties have "everything to play for".
"Huhne was a popular and, by all accounts, assiduous MP, and many in Eastleigh will be sad to see him go and circumstances of his departure," Lord Ashcroft cautioned. "The Tories should not expect many to switch out of disgust," he added, predicting a "bruising - but fascinating" contest.