WASHINGTON – Republicans now controlling the House promised Thursday to slash domestic agencies’ budgets by almost 20 percent for the coming year, the first salvo in what’s sure to be a bruising battle over their drive to cut spending to where it was before President Obama took office.

“Washington’s spending spree is over,” declared Paul Ryan, the House Budget Committee chairman who announced the plan. “The spending limits will restore sanity to a broken budget process,” he said, returning “to pre-stimulus, pre-bailout levels.”

Republicans won’t get everything they want. Democrats control the White House and Senate, and House Republicans may have second thoughts about the magnitude of the cuts.

The White House says the GOP effort could cause widespread furloughs of federal employees, force vulnerable people off subsidized housing, reduce services in national parks and mean less aid to schools and police and fire departments.

House Republicans are seeking to keep their campaign promise to cut $100 billion from domestic programs. The initial cuts would win approval over the coming weeks as Congress wraps up the long-overdue 2011 budget. The second stage would come as the House GOP advances a fresh round of spending bills for the 2012 budget year, which begins Oct. 1.

The hardest hit agencies would include the Food and Drug Administration, the Internal Revenue Service and the departments of Commerce, Housing and Urban Development and Agriculture, according to partial details released by the House Appropriations Committee. Foreign aid on an annualized basis would take a 6 percent cut. Congress’ own budget would be barely touched.

Conservative Republicans want even greater cuts, and they’ll be given the chance to impose them in a freewheeling floor debate scheduled for the week of Feb. 14.

In Thursday’s plan:

The Department of Homeland Security would face a budget freeze instead of the 3 percent increase proposed by Obama.

Rapidly growing spending on veterans’ health care appears likely to be largely untouched.

Republicans would scale back Obama’s proposed 4 percent, $23 billion increase for the Pentagon — the military budget would grow by just $10 billion.

Popular programs such as health research and federal aid to school districts appear likely to take a hit when lawmakers write the spending bill for the departments of Education, Labor and Health and Human Services. Republicans promise not to cut the minimum $5,550 Pell Grant for low-income college students.