President Barack Obama and allied Senate Democrats are sparring with House Republicans on non-budget related items attached to a budget measure that would keep the government funded for the rest of the fiscal year and avoid a shutdown of non-essential government services.

Lawmakers and the White House are working to resolve an impasse on budget negotiations ahead of a midnight Friday deadline to keep hundreds of thousands of government workers on the job.

The size of cuts Republicans are seeking is $40 billion compared to current funding levels. That figure is $80 billion below Obama's request last year for the fiscal 2011 year which ends on September 30.

It makes it tough to win the future, when you haven't passed the budget from last year, Obama said on Wednesday at an event in Philadelphia highlighting clean energy for the 21st century.

Some folks are trying to inject politics in what should be a simple debate about how to pay our bills. They're stuffing all kinds of issues in there - abortion and the environment, healthcare. There's time to have those discussions but that time is not now, Obama said at a Philadelphia event about the future of clean energy in the economy.

Boehner on Tuesday told reporters that Republicans are fighting for the largest cuts possible and policy riders attached to the bill, which are non-budget related items.

White House spokesman Jay Carney said Tuesday what separates House Republicans and Senate Democrats allied with the White House are the composition of cuts being proposed.

Choices need to be made based on priorities like funding for education, funding for medical research, funding for Head Start, and not as I've said before, funding for highway earmarks or military spending that the Pentagon has already said it does not want and does not need.

If we don't reach common Ground by Saturday, the government shuts down, Obama said.