WASHINGTON — Republicans rallied solidly against Democrats’ proposed $1.9 trillion COVID-19 relief bill as lawmakers awaited a decision by the Senate’s parliamentarian that could bolster or potentially kill a pivotal provision hiking the federal minimum wage.

Despite their paper-thin congressional majorities, Democratic leaders were poised to push the sweeping package through the House on Friday. They were hoping the Senate, where changes seem likely, would follow quickly enough to have legislation on President Joe Biden’s desk by mid-March.

By late Wednesday, not one Republican in either chamber had publicly said he or she would back the legislation. GOP leaders were honing attacks on the package as a job killer that does too little to reopen schools or businesses shuttered for the coronavirus pandemic and that was not only wasteful but also unscrupulous.

“I haven’t seen a Republican yet that’s found something in there that they agree with,” said House Minority Leader Kevin McCarthy, R-Calif. “I think all Republicans believe in three simple things: They want a bill that puts us back to work, back to school and back to health. This bill is too costly, too corrupt and too liberal.”

The hardening opposition suggested that Biden’s first major legislative initiative could encounter unanimous GOP opposition. That was a counterpoint to the new president’s refrain during his campaign about bringing the country together.

By Wednesday evening, the most suspense was over a decision anticipated from Elizabeth MacDonough, the Senate’s nonpartisan arbiter of its rules, that promised enormous political and legislative consequences.

The relief bill includes a provision that over five years would hike the federal minimum wage to $15 an hour.

The parliamentarian is involved because Democrats are pushing the overall $1.9 trillion measure through Congress under special rules that will let them avoid a Senate filibuster by Republicans.

Those same rules prohibit provisions with only an “incidental” impact on the federal budget because they are chiefly driven by other policy purposes. The parliamentarian decides if a provision passes that test. With Republicans strongly against the increase, the only way for it to survive is by including it in a filibuster-proof bill like the COVID-19 relief measure.