MPs turned on their regulator over plans for a pay hike to £74,000 - with one Cabinet minister telling it to "stick" the rise.
Education Secretary Michael Gove led a growing backlash against the proposals, dismissing the Independent Parliamentary Standards Authority (Ipsa) as a "silly organisation".
The intervention came after all three main party leaders condemned the idea of an increase at a time when the rest of the country is suffering austerity.
Labour's Ed Miliband and Liberal Democrat Nick Clegg immediately said they would shun the extra money - although David Cameron stopped short of committing himself.
Ipsa's chairman Sir Ian Kennedy remained defiant after announcing the new package for consultation, insisting politicians' pay had to "catch up" after years of being suppressed.
He said the £4.6 million extra salary costs would be offset by curbs to pensions, "golden goodbyes", and expenses - meaning the overall burden on the taxpayer would only go up by £500,000 if the deal took effect after the 2015 general election.
The regulator has been given final responsibility for setting pay and pensions, meaning there would have to be a change in the law to block its decisions.
However, many MPs are already furious at Ipsa's expenses regime, and some have suggested they could back such a move in order to destroy its authority.
Mr Gove delivered the most blunt response yet from a senior figure. Asked during a school visit whether the rise should go ahead, the Tory minister replied: "Absolutely not. MPs are incredibly well paid at the moment anyway, as are ministers.
"It is an absolute privilege to be an MP or a minister. This organisation Ipsa, it is a bit of a silly organisation anyway. And as far as I am concerned, pay rise - they can stick it."