WASHINGTON -- Congressional leaders appeared to be moving closer to a budget deal in the final hours before a government shutdown Friday.

As a midnight deadline to avoid a shutdown fast approached, Democrats said they were reviewing the details of a tentative agreement, officials told The Associated Press. 

Republican leaders in the House of Representatives summoned their rank and file to a late night meeting for what aides said would be an update on the talks. If both sides agreed to the deal, then Congress would pass another stopgap measure to keep the government running while the deal could be written into a bill. 

Earlier, the White House held out hope that deal could be reached.

"We're still talking, so I guess you could say we remain hopeful. But the clock is ticking," a senior White House adviser told Fox News.

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House Speaker John Boehner called President Obama Friday evening but it's not known what he told him. Senate Majority Leader Harry Reid is expected to speak later Friday.

But Republican leaders made clear in a memo to their members there is no budget deal yet.

"We would like to clear up some confusion and relay that there has not yet been a deal reached.The negotiations are ongoing," the leaders wrote. 

It remains to be seen what an agreement, if it is reached, would look like.

Earlier, a government shutdown appeared inevitable as both sides pointed fingers at one another over ideology and spending and couldn't agree on what was holding up a deal.

House Minority Whip Steny Hoyer said comments by both Reid and Boehner are both accurate -- they don't agree and they do.  

"What Reid believes is that there has been an agreement on a number that would be acceptable. The speaker believes that until there's agreement on all items there's not an agreement on any item. So I think both are correct in that sense," said Hoyer, D-Md.

Earlier in the day, Reid had emerged on the Senate floor to introduce a bill that had been approved in the House on a party-line vote Thursday afternoon. The one-week continuing resolution to keep government operational called for $12 billion in additional spending cuts and a full funding of the Pentagon for the remainder of the fiscal year ending Sept. 30.

But Senate Democrats offered the legislation not for its approval, but as a vehicle on which to attach a substitute that contains no cuts. It would have to go back over to the House for approval, where Republicans would be loathe to pass it.

As the hours passed, the alternative went nowhere and both sides remained defiant in their willingness to give ground.  

Reid said the late hour had come to pass because Republicans were holding up a deal over ideology, specifically funding for Planned Parenthood. Speaking to reporters before he reached the floor, Reid said everything relating to a budget is resolved -- including a deal to cut $38 billion off the current operating budget from fiscal year 2010. 

"It is an ideological battle it has nothing to do with fiscal," Reid said. "It has everything to do with women's health. It was the only issue that was left undone when we left the White House last night. ... We agreed on spending cuts and they still are not happy."

"And by the way," Reid added from the Senate, "that does not include abortion. It is illegal to use federal funds for abortion services. So anyone who says this debate is over abortion isn't being truthful. It is about simple and important health services."

But Republicans said Reid is totally off the mark. Emerging from a Republican caucus meeting, Boehner said a deal hasn't been reached.

"Almost all of the policy issues have been dealt with and there is no agreement on the spending level and we're working to get there," he said. "I'm hopeful we'll be able to come to some agreement, but we're not going to roll over and sell out the American people like it's been done time and time again in Washington." 

Earlier, Boehner urged the White House and Senate Democrats to "get serious" about cutting spending by passing the short-term bill.

"This is the responsible thing to do to support our troops and keep our federal government open," he added. 

Senate Minority Leader Mitch McConnell said the claims of ideology are a red herring. 

"This plays nicely into a political strategy they've decide on to distract people from their own fiscal recklessness," McConnell, R-Ky., said, arguing that Democrats "abdicated" their responsibility to fund the government last year. 

Urging Democrats to "take baby steps" toward reducing the deficit, McConnell said approving the short-term extension passed by the House will buy time to finish off the loose ends of a deal that McConnell predicted was close at hand. 

"Nothing in the troop funding bill ... won't be included in the final package. So let's not disrupt and derail that agreement." McConnell said.

Hoyer said that it was unlikely that the Democrats would agree to a possible compromise position that would allow Title X funds for women's health care to be used as block grants, saying it would be inconsistent with the party's policy towards women.

On the other side, a spokesman for Rep. Mike Pence, R-Ind., who authored the language to defund Planned Parenthood, said he would not blink from his position, especially because his amendment to defund one group did not reduce the total health care dollars available to women.  

"It has been erroneously reported in the media that Congressman Pence has signaled a willingness to accept a compromise on the Pence amendment in the negotiations over a long-term continuing resolution. These reports are inaccurate. Congressman Pence has made no statement concerning the ongoing negotiations and remains committed to the Pence Amendment and will continue to work with colleagues to include this measure in any final legislation," said spokesman Matt Lloyd.

Obama vowed to veto any short-term bill, calling it a "distraction" from the longer term negotiation. That led one pro-life House Democrat to say Republicans need to drop their insistence on cutting funds to Planned Parenthood to get the longer-range deal done.

"I believe that if that's what is standing in the way of being able to fund our troops in harms' way then I think it's a mistake," said Arkansas Rep. Mike Ross, who voted for the Republican-sponsored short-term House resolution.