House and Senate negotiators aim to introduce a $1.2 trillion spending bill by Wednesday to avoid potentially messy battles that forced partial government shutdowns in January and February, according to members and aides involved in the talks.

Three major obstacles remain: funds for the $12.9 billion Gateway commuter railroad tunnel under the Hudson River between New Jersey and New York that President Donald Trump wants to block; money for a border wall sought by the president; and a fight over funding for Planned Parenthood.

There are signs that compromises could be reached on each, although Trump can be a wild card in any talks.

Introducing the measure by mid-week would allow the House to vote on it by March 16 and give the Senate a week to complete action before the shutdown deadline on March 23.

Lawmakers are writing the omnibus spending bill to comply with a two-year, bipartisan budget cap agreement enacted in February. The measure will include an $80 billion increase in defense spending and will raise non-defense spending by $63 billion. 

Trump Demands Throw Wrench Into Lawmaker Talks on Spending Bill

Appropriations committee members have agreed to a tentative framework and are leaving the most difficult issues to be resolved by the top Republican and Democratic leaders of the House and Senate.

The transportation section of the spending bill would provide $900 million to start the Gateway tunnel, which is part of a $30 billion series of repairs and expansions for travel between New Jersey and New York. The tunnel would supplement a century-old tube that provides the only rail link between New Jersey and Manhattan and is regarded as critical for the Northeast economy.

Trump is trying to kill federal funding for Gateway, contending New York and New Jersey must pay more, Transportation Secretary Elaine Chao told a House committee last week. A compromise might be reached if the money is allowed to remain in the Transportation Department budget but Congress doesn’t direct the agency to spend it on the project.

Nine Republicans from New York and New Jersey, including Representatives Peter King and Leonard Lance, on Friday sent a letter to House Speaker Paul Ryan of Wisconsin in support of the tunnel. The letter argues that the passenger and freight traffic along the Northeast Rail Corridor “is critical to the economy of the entire country.”

“We urge you to reject any effort to jeopardize this project of national significance and ask that we meet with you personally,” they wrote.

On abortion, lawmakers must reconcile the House and Senate versions of the Department of Health and Human Services spending plan. The Senate measure would prevent the Trump administration from taking money away from abortion providers like Planned Parenthood. The House bill, in contrast, would end family planning and teen pregnancy programs that have sent funds to Planned Parenthood for non-abortion services.

A senior Republican lawmaker said a potential compromise would be to keep both chambers’ language out of the final bill.

On Trump’s demand to build a wall at the U.S.-Mexico border, Democrats appear willing to provide $1.6 billion in border security funds for the Homeland Security Department if Republicans agree to protect undocumented immigrants brought to the U.S as children from deportation.

Because that protection is the subject of a court battle that may last beyond the Oct. 1 start of the next fiscal year, Republicans may conclude they have little to lose by keeping the protection until then. Many lawmakers want a permanent solution for the so-called dreamers this year but that looks less likely as the November election approaches.