Lord Ashcroft's poll puts them 15 points ahead of Ukip, but they trail Labour by nine points nationally.
With a week to go, the party's eight-point lead is too small for comfort.
Cameron fears the collapse of the coalition. Labour fears a more popular centre-left leader.
Targets are missed on two fronts, with net migration up by 212,000 and borrowing up by £1.9bn.
The Chancellor's denouncement of those who want to "pull up the drawbridge and shut Britain off from the world" applies to a significant number in his own party.
A new poll shows the party trails in 25 must-win Conservative seats.
The PM recognises how any hint that he could depart could galvanise the "No" campaign - but he is preparing for defeat.
The combined attacks by the Lib Dems and Labour are further weakening public support for Gove's project.
Labour knows the state isn’t perfect. But the coalition is giving power to big corporations, not to people.