Nick Clegg has warned the public would not understand it if MPs were awarded a bumper pay rise.
The Deputy Prime Minister said that he would not accept an award well in excess of the pay increases for other public sector workers.
His warning came amid reports that the Independent Parliamentary Standards Authority (Ipsa) is considering setting a pay rise of around £7,500, taking an MP's salary to £75,000.
Speaking at the first of his planned Whitehall news conferences, Mr Clegg made clear that a rise on such a scale would be unacceptable to voters.
"My own view is that the public would find it impossible to understand - particularly as (there are) millions of people in the public sector whose pay is only increasing by 1% - that their parliamentary representatives at a time like this would be receiving pay increases far in excess of that 1% increase," he said.
"Speaking for myself I would certainly seek to do whatever I can to make sure that either this decision is not taken in the first place - but that's out of my hands - but, secondly, if were to be taken, not to take that pay increase."
Prime Minister David Cameron has already urged Ipsa to "show restraint" warning it would be "unthinkable" to make Westminster more expensive to the taxpayer, while Labour leader Ed Miliband has also signalled his opposition to such a large increase.
According to weekend newspaper reports, sources have indicated the regulator would suggest raising MPs' pay to £75,000 a year, in a series of upratings starting in 2015, coupled with much higher pension contributions.
Mr Cameron said he did not know what the independent body would recommend. But he added: "Whatever Ipsa recommends we can't see the cost of politics or Westminster going up. We should see the cost of Westminster go down."
Conservative Party chairman Grant Shapps said it would be for the next parliament to decide on the Ipsa recommendations but that the Tory manifesto would "more than likely say that in the next parliament the costs of politics should fall".