Subsidised food at Stormont's canteen costs taxpayers about £500,000 a year, according to a member of the body which manages the assembly.
The figure was revealed as the first minister, DUP leader Peter Robinson, called for the subsidy to be removed.
Assembly Commission member Pat Ramsey of the SDLP said the four-year catering contract was in its final year.
However, he said he was concerned "the joint head of the executive was seeking to dictate terms to the legislator".
MLAs passed a motion on Monday calling for the assembly to cut its running costs following the Treasury's Spending Review.
Mr Ramsey told the BBC the Assembly Commission "would be cutting our cloth no different to any other department" and he did not believe the debate was necessary.
"If Peter Robinson or any other minister of the executive was concerned about the functioning of the assembly commission, they could speak to us at any time," he said.
The assembly commission's budget for the current financial year is £50.4m, and efforts are being made to identify reductions of either 2.5% or 5% over each of the next four years.
The motion, proposed by Mr Robinson, stated the cuts should be in line with the reductions facing executive departments.
The DUP leader said the assembly should be seen to take a leadership role on the issue.
He repeated the willingness of DUP ministers to take a voluntary reduction in their salaries, and said food at Stormont should not be subsidised at a time when people are having difficulty paying their food bills.
Although Mr Robinson was speaking in his capacity as an individual MLA, some other members argued he was creating a dangerous constitutional precedent, given his role as first minister, in pressurising the assembly which is meant to bring the executive to account.
SDLP assembly member Alban Maginness accused the DUP of hypocrisy on the issue.
Mr Maginness said the motion proposing cost reduction was in contrast to the DUP's position on cutting the number of MPs and constituencies.
He said it was "a bit rich" for Mr Robinson to talk about the subsidy to food at Stormont when he previously claimed his £400 a month food allowance at Westminster.
It is not unusual for canteens in public organisations to be subsidised including the BBC.