Labour leadership contenders Andy Burnham, Yvette Cooper and Liz Kendall today signalled they will reject the planned MPs' 10% pay rise or give it to charity.
The Shadow Health Secretary piled pressure on fellow Labour leadership contenders after Tweeting that he would not take the £7,000 cash hike recommended by the independent pay body IPSA.
Ms Kendall's camp then said she stood by her position - outlined two years ago - that if IPSA went ahead with the rise, from £67,000 to £74,000 a year, she 'won't take it'.
And a spokeswoman for Ms Cooper added: "Yvette thinks its wrong to have 10% at a time when the deficit is still high and public services are about to be cut.
"She thinks IPSA should withdraw it and the Prime Minister should step in to prevent it. If it goes through she won't take it, but she thinks IPSA and the Prime Minister should sort it out before that."
But Downing Street said that David Cameron will take the increase in his MP's salary if the Independent Parliamentary Standards Authority refuses to change tack.
Asked if the Prime Minister would donate his increase to charity, his political spokesman replied: "He's an MP, so if IPSA set the pay of MPs, he will take the pay that MPs get."
Mr Burnham, who has been arguing that NHS staff should get the pay rises due to them, Tweeted today that he wanted to be consistent in his opposition to Parliament being treated differently.
Deputy Labour leadership contender Stella Creasy also said she would not take the pay rise and would instead ask her local constituents where to direct it.
Technically, if the pay watchdog goes ahead with the pay rise, there is nothing MPs can do to stop it going into their bank accounts. But they can decide whether to pocket the cash or donate it elsewhere.
A spokeswoman for Harriet Harman said that it was 'upto individuals' to make their own decisions and the leadership candidates were free to make their positions clear.
When asked if Ms Harman would take the money, the spokeswoman told The Huffington Post UK "I would be surprised if she took it", given her staunch belief that now is not the time for MPs to get rises greater than public sector workers.
She added: "There has been a huge backlash against these proposals. IPSA are conducting a review, let's see what they come up with."
Under the IPSA plans, Mr Cameron's total pay package would increase from £142,500 to £149,440 a year.
With trade unions already furious over their own pay freezes, Downing Street risks a public as well as public sector backlash over the increase in pay rates.
However, many MPs in all parties believe that their pay has lagged behind in recent years and point out that the decision is now out of their hands, following the creation of IPSA in the wake of the expenses scandal.
Mr Cameron has been told by senior backbenchers that he would be guilty of 'gesture politics' if he handed his own pay rise to charity.
Several rank and file Tory MPs believe ministers, who earn £134,565 a year, should not be lecturing their lower paid colleagues on how to deal with the pay rise.
IPSA claim the proposals are “cost-neutral” to the tax-payer thanks to reforms of the expenses system, pensions and resettlement funds.
Unless "new and compelling evidence" emerges by the end of the month, the move will be confirmed - with the rise backdated to May 8.
When the increase was first proposed in December 2013, Mr Cameron threatened to act, saying it was “simply unacceptable” for MPs to receive such a rise at a time of pay curbs on public sector staff and wider austerity measures.
Mark Serwotka, the head of the PCS union, said: “It would be grossly hypocritical for any MP who voted for years of pay cuts for public sector workers to accept a 10% increase for themselves.”
Yesterday the Prime Ministers' spokeswoman said: "There are effectively two jobs that a minister does, there's the job they do as an MP and the job they do as a Minister. And the PM in setting ministerial pay has frozen that for five years. It's for IPSA as an independent body to determine the MPs' pay element."
The £7,000 rise in the MP element of a minister's pay will go some way to making up for the five-year freeze imposed by No.10 just last month.