A top Senate appropriator said Tuesday the final omnibus spending bill would likely not include a provision to defund “sanctuary” cities that do not cooperate with federal immigration authorities.

House Freedom Caucus Chairman Mark Meadows, R-N.C., suggested in two posts on Twitter that Congress should withhold federal grants for sanctuary cities in the omnibus. His remarks follow the Trump administration’s decision to sue California over three state immigration laws, escalating a battle over sanctuary jurisdictions that began shortly after President Donald Trump took office.

“I don’t think it’s going to happen in the Senate. I mean Congressman Meadows may feel like that is a good idea but practically speaking that will be really difficult to get done,” Senate Homeland Security Appropriations Subcommittee Chairman John Boozman, R-Ark., said in an interview.

While conservatives like Meadows hold some sway in the House, Republicans need the votes of nine Democrats to get any legislation through the Senate. That has been a difficult task, especially on immigration issues.

For example, a proposal last month by Sen. Patrick J. Toomey, R-Pa., that would authorize the federal government to block sanctuary cities, states and counties from receiving economic development grants was effectively rejected. It fell six votes short of advancing on a procedural motion.

“Why should Congress continue pouring taxpayer dollars into cities that defy federal immigration law? That shouldn’t happen in America — a nation of law and order,” Meadows tweeted Monday.

A federal judge earlier this month allowed the Justice Department to withhold, for now, a $1 million grant to California because of its sanctuary policies. And last year, the House passed a bill that would revoke a local jurisdiction’s eligibility for federal grants if they don’t comply with federal requests to detain undocumented immigrants who commit crimes. The Senate has not acted on the bill.

In announcing the lawsuit against California, Attorney General Jeff Sessions told law enforcement officials last week that the administration would “fight these unjust, unfair and unconstitutional policies.”

Trump is expected to talk about sanctuary cities during his visit to California, where he will also inspect border wall prototypes near San Diego. A senior administration official told reporters traveling with the president that the administration asked Congress to withhold grants from sanctuary cities as part of the omnibus spending bill.

Sen. Robert Menendez, D-N.J., said that if Congress tries to withhold grants from sanctuary cities it would be a “huge problem” for him and many other Democrats.

“I think it is outrageous. Those grants are ultimately critical to communities to protect their citizens,” he said.

In a related issue on the spending bill, Boozman said he expects funding for the border wall to be one of the last items to be settled by appropriators and GOP leaders before the omnibus text is released. The administration is seeking $1.6 billion in fiscal 2018 for construction along the U.S.-Mexico border. Current government funding expires March 23.

Senate Minority Leader Charles E. Schumer, D-N.Y., said Democrats remain opposed to the wall but are open to funding border security measures.

“We will fight for real border security, not fake border security, plain and simple. We’re not drawing red lines in the sand as we negotiate, “ Schumer said.

Ryan McCrimmon and Dean DeChiaro contributed to this report.