A former member of the body which set MLAs' pay has said he is "amazed" that Northern Ireland's five main political parties are now expressing concern about its decision four years ago setting their pay rises.
Alan McQuillan said they all signed up to securing an annual increase if inflation was greater than 1%, and he accused them of now adopting a different position because of public pressure.
He was of the three-member Financial Review Panel which set MLAs' salaries in 2016.
Mr McQuillan was speaking after a joint statement from the DUP, Sinn Fein, SDLP, Alliance and Ulster Unionist leaders opposing a salary hike which saw their pay rise by £1,000 following the restoration of devolution.
They are due another £500 increase in April. There was widespread anger across Northern Ireland that the politicians were being rewarded after three years of stalemate at Stormont. Their salaries will go up from £49,500 to £50,500.
In their statement, the leaders said the increase "came as a surprise to all parties".
They said: "We share the broad public dismay at this development, only a matter of days after the Assembly and institutions have been fully restored.
"We have had a range of concerns over time around recommendations emerging from the Independent Financial Review Panel.
"We are jointly asking the Assembly Commission that any pay proposal is immediately deferred until the work of the Financial Review Panel has been comprehensively reviewed, and a new panel has the opportunity to consider this matter again and produce a fresh determination."
However, Mr McQuillan said: "I am amazed that they are surprised by their pay rise. The system giving them one has been in place since 2016.
"Before it was finalised, we conducted an extensive consultation exercise with every MLA and all the parties.
"I do not recall a single objection to the decision to increase MLA pay by 1% annually if inflation was greater than 1%."
Mr McQuillan said that the public reaction to learning that Stormont politicians were securing a £1,000 pay rise after three years of stalemate had caused the parties to panic.
"None ever expressed any concern to us before about pay going up," he said. "Some did in the past raise questions when we put very tight controls on their expenses and on getting value for the money that was spent."
People Before Profit MLA Gerry Carroll said that stopping the £1,000 pay hike didn't go far enough. "MLAs earn double the average workers' wage here and people are angry about that. They see Stormont as a giant gravy train."
Following the leaders' statement an Assembly spokesperson said that Speaker Alex Maskey was "mindful of the concerns" and would invite Assembly Commission members and members due to be appointed to the Commission to attend a meeting today "to discuss how those concerns might be addressed".
In their statement, the five leaders noted that if the pay increase could not be halted, several MLAs and parties indicated they would donate it to charity.
West Tyrone representative Daniel McCrossan said he would give the money to local mental health charities.
South Down MLA Sinead Bradley said she was joining him and it was "the right thing to do at this time".
Mr McCrossan said that the public was "rightly angered and outraged" by the hike.
"After three years of no government here and public services falling apart, a pay rise for MLAs shouldn't even be the last thing on the table, never mind the first," he said.
"This pay rise was not voted on and was not agreed by SDLP MLAs.
"I did not want it nor do I think it's something that we deserve. I am going to donate any increase I receive to local mental health charities. It may not be a lot, but it could make a lot of difference to some people struggling out there."
In his Facebook post, Mr McCrossan said that nurses, teachers and civil servants were being "forced to fight for a pay rise which they deserve". He added: "There's a lot of anger and frustration out there and huge challenges ahead."