The independent body, which formerly set the salaries for MLAs has urged the Secretary of State to halt their payments after three months if direct rule is introduced.
The Independent Financial Review Panel (IFRP) set MLAs expenses and salaries before their roles expired last June.
In law it still exists, but the posts are vacant.
In the wake of the Assembly elections and fresh negotiations to create a working government the three members of the body, Pat McCartan, Alan McQuillan, and Etta Campbell have written to James Brokenshire stating that payments in the absence of a functioning assembly and executive would be "unjustifiable".
"If the government is therefore forced to suspend the assembly by Order in Council we strongly recommend that you consider strictly limiting the period for which members may draw salaries and expenses - perhaps to a period of three months to allow completion of any negotiations," the letter said.
The letter also said that any future system for payments to MLAs "needs strong and independent administration, supervision, and audit".
Speaking on the BBC, Mr McCartan said the proposals were to ensure "financial propriety" and expedite an agreement between the parties at Stormont.
"Frankly we think three months is quite long enough for in order to be able to reach some accommodation to get people back into the legislative assembly for the work they're paid to do," he said.
SDLP South Down MLA Colin McGrath said that MLAs should be "paid to do our job" and that Arlene Foster should step aside to allow Stormont to get up and running again.
Alliance East Antrim MLA Stewart Dickson said three months to reach an agreement was "reasonable".
The parties at Stormont have three weeks to form an executive and if this cannot be achieved within that time frame, then conceivably another election could be called. If no agreement can reached to create a power-sharing government we could see a return to direct rule from Westminster.
When Stormont was previously suspended in 2002 following the 'Spygate' affair, assembly members were paid two-thirds of their salaries until an agreement was finally reached in 2007.
The annual salary for an MLA for the financial year commencing April 1, 2017 is £49,500, an increase of £500 on the current financial year. However, there is additional payment for committee chairs and deputy chairs, members of the assembly commission, members of the speaker's office as well as ministerial positions.
