WASHINGTON — Applications will be accepted starting Feb. 18 for temporary deportation relief for immigrants who were brought to the U.S. illegally as children as part of protections under President Barack Obama’s new immigration plan.

Expanding the Deferred Action for Childhood Arrivals program is the first part of Obama’s plan — and exactly what the new Republican Congress has tried to prevent by withholding full funding this year for the Homeland Security Department.

As the U.S. Customs and Immigration Services on Saturday announced the program’s launch, Republicans said they would prevent Obama’s plans from taking effect.

“The American people have spoken loud and clear that they don’t want President Obama to change our immigration laws on his own,” said Rep. Bob Goodlatte, R-Va., chairman of the House Judiciary Committee. “Congress must fight the president’s actions, including taking legal action so that we restore the separation of powers and protect individual liberty.”

Funding for the Homeland Security Department, which handles immigration issues, is set to run out Feb. 28, and the Republican-led House has approved new funding — but with stipulations that the money not be used for Obama’s new immigration plan. They also require ending the DACA program.

The House funding legislation is expected to stall in the Senate where it will face resistance from Democrats — and possibly some Republicans — in a key test vote Tuesday.

Obama has said he would veto any measures that roll back his executive actions on immigration, and it remains unclear how Congress will proceed to meet its goals of stopping the White House plan while also funding the Homeland Security Department.

The president last fall pledged temporary deportation relief for up to 5 million immigrants in the U.S., which would allow some to work here. He said he took the unilateral action because Congress had repeatedly failed to deliver immigration-reform legislation. The first part of his plan is expansion of the 2012 program for so-called “dreamers,” those who were brought to the U.S. as children. More than 500,000 young immigrants are already in the program.

Later this year, parents of citizens can also apply for relief, along with other groups.

In a statement Saturday, the U.S. Citizenship and Immigration Services department said Feb. 18 “will be the first day to request DACA under the revised guidelines established as part of President Obama’s recent announcements on immigration.”

“USCIS advises the public to be extra careful to avoid immigration scams” and offered information online “to learn how to identify and report scams, and how to find authorized legal assistance at little or no cost.”