'Nonstop' negotiations on passing a federal budget for the remainder of the fiscal year were continuing ahead of a Friday deadline to avert a shutdown of a big portion of the government, as House Republican and Senate Democrats allied with President Obama sought to break an impasse that could put hundreds of thousands of workers on leave without funding in place.

President Barack Obama spoke with House Speaker John Boehner on Wednesday and told the President he was hopeful that a shutdown of some federal government services could be avoided ahead by a Friday deadline.Boehner, R-OH told the president he remains hopeful a deal can be reached and that talks would continue, Boehner's office said in a statement.

The three minute conversation took place ahead of a trip by Obama to Pennsylvania where the President is will be holding a town hall meeting about the future of clean energy in the economy.

Senate Majority Leader Harry Reid said on the Senate floor on Wednesday that negotiations continue nonstop.

Boehner is reportedly seeking $40 billion in cuts to the federal budget from current spending levels, up from $33 billion which top Democrats say negotiators were trying to reach. Boehner has previously said there had never been an agreement on the $33 billion figure.

People ask why this is so difficult. They ask, 'Can't you just get it done?' I understand and share their frustration. But this is why it's so tough. It's like trying to kick a field goal through moving goalposts, Reid said.

We stand here with fewer than 72 hours on the clock. It's time to get to work. It's time to get the job done, he said.

On Tuesday, Obama said he would call back Boehner, Reid and their negotiating teams back to the White House at the conclusion after talks at the White House in which the leaders failed to reach an agreement. No deal was struck at the Tuesday meeting.

Obama is set to attend a meeting of civil rights group National Action Network in New York on Wednesday evening.

If a shutdown does begin this Friday, hundreds of thousands of federal employees would be furloughed, tax refunds from paper-based filers would not be processed and federal loans for small businesses and new federal home loans would not be processed, Senior Obama Administration officials said on Wednesday.

The number of federal employees furloughed by a shutdown in 2011 would be in the same vicinity as a 1995 shutdown, which saw 800,000 employees furloughed in the 21-day span needed to reach an agreement once the shutdown began, a senior official told reporters during a conference call.

The longest previous shutdown in U.S. history took place for 21 days starting from December 16, 1995 to January 6, 1996.