WASHINGTON (AP): A House panel Tuesday unveiled legislation to begin building President Donald Trump’s long-promised wall along the U.S-Mexico border. Mexico, however, will not be footing the bill.

The move by the House Appropriations Committee again puts the Trump administration and its allies on Capitol Hill on a collision course with Democrats who oppose the wall and succeeded in blocking a request by Trump to deliver the money when passing an omnibus spending measure earlier this spring.

Democrats objected to the funding and significant opposition surfaced among Republicans as well, many of whom have problems with the wall. The administration and congressional Republicans took a pass on forcing the issue in May but vowed to fight for the wall this summer and fall.

During last year’s campaign, Trump bragged that Mexico would pay for the wall but he’s never come up with a serious plan to deliver on his boast. Instead, the $1.6 billion down payment for the wall will be added to the government’s almost $20 trillion debt.

The wall money is embedded in a $44 billion homeland security funding bill released on Tuesday by the House Appropriations Committee. A House Appropriations subcommittee is slated to give the measure a preliminary OK on Wednesday. GOP leaders hope to pass the measure before adjourning for the August break.

The fight over funding the wall is a major obstacle to funding government agency operations for the budget year beginning Oct. 1 and some conservatives are threatening to shut the government down if the wall is not included. Rep. Mo Brooks, R-Ala., has raised the threat as part of his GOP primary campaign against appointed Sen. Luther Strange, threatening to filibuster any funding bill that fails to include money for the wall project.

Trump himself reacted to news reports suggesting Democrats had bested him on the earlier catchall spending bill by taking to Twitter to complain about Senate filibuster rules and declaring that: “Our country needs a good ‘shutdown’ in September to fix mess!”

Democrats quickly signaled they’re eager for the fight.

“Once again, Republicans are trying to put American taxpayers on the hook for the multi-billion dollar boondoggle President Trump swore Mexico would pay for,” said House Minority Leader Nancy Pelosi, D-Calif. “Trump’s immoral, ineffective and expensive wall is strongly opposed by Democrats and by many Republicans as well. A wall of bipartisan opposition is the only thing House Republicans are trying to build here.”