The Trump administration wants a list of programs that could be impacted as the longest ever government shutdown drags on, a senior official at the Office of Management and Budget told CNBC on Wednesday.

The official said in a statement that "prudent management means planning and preparing for events without known end-dates."

"As OMB continues to manage this partial lapse in appropriations, unfunded agencies are being asked to continue to share with OMB an ongoing list of programs that could be impacted within the coming weeks," the official said.

The Washington Post reported, citing people familiar with the matter, that the request for a list by Friday came from acting chief of staff Mick Mulvaney. He requested that the list include programs that would be affected if the lapse in funding continued into March and April, the Post reported.

The news comes as the partial shutdown notched its 33rd day, with no end in sight as roughly 800,000 workers go without pay. On Thursday, the Senate is scheduled to hold votes for competing proposals to fund the government through Feb. 8, but neither measure is expected to pass. Democrats and Republicans have been locked in a standoff over President Donald Trump's insistence that any funding bill include $5.7 billion for a wall along the U.S.-Mexico border.

Earlier Wednesday, the White House's top economist said that the economy could see almost zero growth if the shutdown drags on for a full quarter.

"If [the shutdown] extended for the whole quarter, and given the fact that the first quarter tends to be low because of residual seasonality, then you could end up with a number very close to zero in the first quarter," Kevin Hassett told CNN.

— CNBC's Eamon Javers and Thomas Franck contributed reporting.