(Jenny Starrs/The Washington Post)

The House voted Wednesday to approve a roughly $1.1 trillion spending bill that includes more than $15 billion in defense spending and $1.5 billion in money for U.S. border security, setting up a vote later this week in the Senate ahead of a deadline to keep the government open past Friday.

The spending measure, which passed 309 to 118 and funds the federal government through September, is expected to clear the Senate easily this week before budget battles begin anew. Some House Republicans are already looking ahead to the fiscal year that begins in October as a chance to demand new defense spending and exact greater concessions from Democrats in the next round of spending talks.

“This marks the beginning of a new era,” said House Speaker Paul D. Ryan (R-Wis.). “No longer will the needs of our military be held hostage by the demands for more domestic spending.”

Republicans secured $15 billion from an off-budget war fund, which they described as the first step to breaking years of equal spending increases for defense and non-defense spending. The argument over that parity has been one of the fiercest fights in the past 10 years of budget negotiations.

Democrats said the new spending measure continues the even treatment because they have never opposed using the war fund for military expenses. GOP members see the latest negotiation as an opening to demand greater money in the future.

House Speaker Paul D. Ryan (R-Wis.), with House Majority Whip Steve Scalise, left, works with House colleagues during a leadership meeting in his office on Capitol Hill last month. (Melina Mara/The Washington Post)

The brewing defense fight marks an immediate shift from the recent bipartisan spending talks to a highly charged debate over setting spending priorities for years to come. It also marks the first time that conservatives, who demanded across-the-board spending cuts under President Barack Obama, have signaled that they might support defense funding increases to help fulfill major elements of President Trump’s agenda.

Defense hawks in the House have already launched an effort to persuade GOP leaders to attempt to repeal the defense spending caps that were set in the 2011 Budget Control Act, also known as the sequester.

More than 140 House Republicans signed a letter Wednesday calling for GOP leaders to scale back those defense cuts as part of the upcoming long-term budget talks. The letter was led by Rep. Michael R. Turner (R-Ohio) and signed by the chairmen of the House Armed Services Committee, the conservative House Freedom Caucus and the Republican Study Committee.

“This is not just a spending issue, this is a security issue,” Turner said in a call with reporters. “Sequestration has required us to do fictional budgeting.”

Republicans have long insisted that capping defense spending could hamper military readiness, but the latest push comes with the backing of conservatives who are often skeptical of spending increase of any kind.

“I’m okay with breaking the caps on the defense sequester,” said House Freedom Caucus Chairman Mark Meadows (R-N.C.). “That’s where the negotiations start.”

The letter marks the first time in recent years that a majority of House GOP members have backed spending increases. Meadows said he chose to back the push for more defense money because he strongly believes that Congress will soon scale back spending on programs like Social Security and Medicare.

Converting conservatives is a small feat for defense hawks, but Congress would have to pass a new law to increase spending — and Republicans would probably need at least eight Democrats to pass the measure in the Senate.

Democrats say they’re happy to discuss spending increases, but only if they benefit agencies beyond the military.

“It is clearly time to lift the budget caps in [fiscal year] 2018, but for more than just the Pentagon,” said Rep. Nita M. Lowey of New York, the top Democrat on the House Appropriations Committee. “Working families, hospitals, schools and local infrastructure need attention just as badly as we need new jets, tanks and ships.”

Complicating matters further, the coming talks are also expected to revisit Trump’s demand for money to begin building a wall along the U.S.-Mexico border. Trump dropped his request for that money in the current measure to clear the way for a final deal, but the White House plans to renew the push for money later this year.

There is also no guarantee that Republicans can unify around the call for defense money. Some conservatives remain skeptical of any attempt to increase spending without corresponding cuts elsewhere in the budget — even if that new money goes to defense.

“In a pure vacuum sense, am I in favor of more defense? Yeah, but we don’t live in that vacuum,” said Rep. Mark Sanford (R-S.C.). “Curtailing spending on all fronts is vital to our national security.”