Public services are suffering in Northern Ireland because of lack of direction from ministers, the head of the civil service has said.
Civil servants are frustrated, David Sterling said, by a stalemate which has put devolved government on hold for a year.
He said "budget certainty" for the next financial year must be secured by February 8 and warned the sums available were due to fall in real terms.
"There is a strong sense of frustration, 23,000 civil servants, we care passionately about the community of people and there is a sense of commitment amongst civil servants to provide good quality public services.
"There is a frustration and we do fervently want to see a return of ministers and functioning Executive and Assembly."
He said civil servants were following policy directions set by ministers a year ago but the circumstances had changed and policies should adjust.
"We have not reached a shutdown point but the reality is public services are suffering as a consequence of this because we are not getting the direction that we need."
Decisions need to be made on spending allocations to under-pressure areas like education and health.
Parliament is due to rise early next month, meaning a delay in passing a spending plan for next year unless there is progress before then.
Mr Sterling said: "In my view it will be incredibly difficult for us if we don't have budget certainty by February 8."
He called for clarity about total cash allocations from the beginning of April for Stormont departments.
If renewed political talks at Stormont do not produce a breakthrough, Northern Ireland Secretary Karen Bradley will be under pressure to step in and draw up next year's budget herself in consultation with civil servants.
Hugh Widdis, permanent secretary of the Department for Finance, said Ms Bradley had not indicated that she was prepared to take such decisions yet.
He added: "The Secretary of State's focus, quite rightly, is very much on getting the devolved institutions back."
The DUP negotiated a confidence and supply arrangement of extra funding for areas like broadband and roads as part of their deal to support the minority Tory Government.
Legislative action at Westminster is needed to spend that within a wider budget, the senior civil servants told the Northern Ireland Affairs Committee of MPs.
Ian Paisley, DUP MP for North Antrim, said the public wanted ministers to spend that money now.
He added: "There are no strings attached, it is a bonus, you have won the lottery, please spend the money."