Public support for the Conservatives has slumped dramatically since the Budget and Labour is now considered more competent, according to a new poll.
Labour has overtaken the Tories as the party rated the most competent and capable for the first time since the coalition formed in 2010, the survey for The Times found.
The opposition party is also ahead of the Conservatives on questions about which party is the most united and which has clear ideas to deal with Britain's problems.
Its surge in the rankings is not due to a boost in support for Ed Miliband's party, because its ratings remain virtually unchanged since March.
The change has been caused by a double-digit drop in confidence in David Cameron's team, with particular bad news for Chancellor George Osborne.
Of those who knew who Mr Osborne was, 45% told pollsters Populus that he should be sacked, compared to 18% who felt he was doing a good job.
With a Government reshuffle widely expected in September, top candidate to be axed is Health Secretary Andrew Lansley - who 53% said should be sacked.
He is followed by Culture Secretary Jeremy Hunt on 48%, who was in the spotlight over the BSkyB takeover bid, and Home Secretary Theresa May on 46%.
The only Tory Cabinet minister to receive a positive rating was Foreign Secretary William Hague, who is tipped by some as a possible replacement for Mr Osborne at the Treasury.
Some 49% said he was doing a good job, against 20% who said he should be sacked.
The proportion of voters who think the Conservatives are "competent and capable" fell by 12%, from 46% in March to 34%.
This puts them two points behind Labour on 36%, who were down one point since March, with the Liberal Demorats behind on 24% - a fall of 6 points.
Mr Osborne's Budget has been heavily criticised and the following weeks and months have seen U-turns on issues including the pasty tax and a fuel duty increase.
On party unity, the Tories fell 14%, from 42% in March to 28%, equal with the Lib Dems who are down one point. Both coalition parties trail well behind Labour on 46%.
Asked which party has clear ideas to solve Britain's problems, the Conservatives were down 11 points from 44% in March to 33%, behind Labour on 36% - who fell two points.
The Liberal Democrats fell nine points to 23%.
Some 40% of those questioned said they would vote Labour - down one point since a similar poll in June - with the Conservatives up one on 34% and the Lib Dems up three on 12%.
:: Populus interviewed 1,501 adults for The Times between July 13 and 15.