An announcement by Republicans that they emerged victorious on earmark reform appeared to be premature Thursday after Democrats said House Minority Leader John Boehner had spoken too soon on any deal.

The fight over earmarks — the funding for lawmakers' pet projects — has held up the first of 12 budget bills for fiscal year 2008 — one that would fund the Homeland Security Department. House Democrats want to pass all 12 bills before July 1.

Republicans want to hold Democrats to an earlier promise to make earmark requests more transparent by revealing where they are designated and which lawmaker is requesting them before the spending bills reach the House floor.

Democrats, led by Appropriations Committee Chairman David Obey of Wisconsin, had said they would release the list of 33,000 earmark requests 30 days before House and Senate appropriators meet in conference committee on the bills. Members of the House would not have an opportunity to contest any particular item on the floor.

On the Senate side, the Senate appropriations homeland security subcommittee advanced its annual spending bill with $16 million in projects.

Early on Thursday, Republicans said they had reached an agreement to restore GOP reforms for appropriations bill to allow debate on the House floor. The agreement also called for the public disclosure of sponsors of pet projects and bans funding secret earmarks in appropriations bills, they said.

Boehner, R-Ohio, praised the alleged agreement as a chance to bring an “end to secret slush funds for earmarks.”

“I think we’ve won this round,” Boehner said.

“The truth is that our Congress declared war on a secret slush fund for spending, and we won,” added Rep. Roy Blunt, R-Mo. “This is a big win for taxpayers, it’s a big win for the media, frankly, it’s a big win for Republicans.”

But top House Democrats told FOX News Thursday afternoon that they had reached only "tentative agreement" with Republicans Wednesday night to ensure that earmarks are attached during the committee process to 10 of the 12 annual spending bills, and that House members have the opportunity to debate and vote on individual pet projects on the floor. In exchange, they said, Republicans agreed to restrictions on the amount of debate time.

According to Democrats in the center of these negotiations, on Thursday Boehner reneged on his promise to limit the amount of debate time. Boehner's aides say he never agreed to such a deal, but would take it to his caucus, which refused to accept the limits on debate.

House Speaker Nancy Pelosi said early Thursday that she was optimistic Republicans will "end their delaying tactics" to reach a deal.

"We will fulfill our pledge to the American people who demanded greater openness and accountability," said Brendan Daly, a spokesman for Pelosi.

On Monday, Obey said he would kill all pet projects if Republican leaders "demagogue" the issue. Republican Reps. Adam Putnam of Florida and David Dreier of California responded that they wouldn't back down from their positions.

This fight "is about what Democrats promised they were going to do," Putnam said, citing Democrats' campaign promise to create "transparency and openness" on the earmark process.

Dreier added that he's been approached by Democrats who say they are concerned that Obey and others in their party are "wrong in doing this."

According to Citizens Against Government Waste, the fiscal year 2007 defense and homeland security appropriations bills contained 2,658 projects at a cost of $13.2 billion. The watchdog group notes that only two of the 11 spending bills were passed by Congress last year. The rest were completed in an omnibus measure, which was stripped of all earmarks as a result of infighting in 2006 that left the legislation for the 110th Congress to wrap.

FOX News' Molly Hooper and Jim Mills contributed to this report.