Senate Republicans delayed the release of their coronavirus relief package Thursday as they struggled to resolve policy disputes and iron out details of the trillion-dollar initiative.

While Senate leaders had hoped to unveil their measure this week, lawmakers said late Thursday that the series of bills they are drafting would require more time and won’t be released until Monday at the earliest.

Speaking on the Senate floor, Majority Leader Mitch McConnell said late afternoon Thursday that they had an “agreement in principle” with the White House, but administration officials asked for more time to review details. A series of bills would be introduced “early next week,” McConnell said.

“Sometimes these things take a lot longer to get the word right or the phrase right,” James Lankford, R-Okla., told reporters earlier. And the attempt to respond to an ever-evolving pandemic means there is no legislative playbook to use as a guide. “You’re writing from scratch and that complicates a lot of things,” he said.

At a Senate GOP lunch, talk focused more on the alligator sausage lawmakers were served than the status of the aid package, according to participants. “The timeline has been pushed back,” said Sen. Marco Rubio, R-Fla.

Several major pieces of the package appeared likely to require more work, based on comments senators have made. Republicans have been seeking to extend expanded unemployment benefits that are set to expire at the end of this month. But they oppose the current law, which adds a flat $600 per week to state benefits, saying it provides more money than many workers would earn on the job.

White House officials shot down an effort by some Republicans to offer a short-term extension of benefits until the plan can be refined. Senators said Thursday their package would offer jobless workers a benefit equivalent to 70 percent of their wages.

But Sen. Ron Wyden of Oregon, the top Democrat on the Finance Committee, said that plan wouldn’t be feasible. He said Labor Secretary Eugene Scalia had told him that benefits couldn’t be tailored to calculate each worker’s wages efficiently enough to get money out the door in a timely manner.

“Everything that they have talked about so far, based on Secretary Scalia’s comments, can’t be administered,” Wyden said.

White House Chief of Staff Mark Meadows told reporters that any delay in the distribution of unemployment benefits could be offset by a new round of tax rebate checks that is also part of the proposal.

[GOP virus aid package: Payroll tax cut out, restaurant deduction in]

Treasury Secretary Steven Mnuchin said Thursday that the payments would be “exactly the same” as in the $2 trillion March aid package and could be distributed as early as August. The prior law provided $1,200 per adult, phasing out above $75,000 in adjusted gross income.

Liability cap

Another major provision that could require refinement is the push to give employers liability protection. The provision would make it harder for workers to win legal judgments if they contract the coronavirus while on the job.

A worker must show that the defendant was “grossly negligent or engaged in willful misconduct” and violated state and local health guidelines. While there had been talk of imposing a cap on liability awards, Sen. John Cornyn, R-Texas, said the bill doesn’t currently contain one “but that’s a possibility.”

Despite the unresolved issues, the broad outlines of the package became clear Thursday. Among other things, it is likely to include $105 billion for schools, $25 billion for virus testing, and an extension of the Paycheck Protection Program that offers forgivable loans to small businesses, with new guidelines to target smaller-sized companies.

And a big policy fight was resolved when President Donald Trump backed down from his quest to include a suspension of payroll taxes. Trump faulted Democrats for opposing the idea, but many Republicans expressed opposition as well, saying it could undermine Social Security revenues and do little to ease financial hardship at a time of mass unemployment.

“The Democrats have stated strongly that they won’t approve a Payroll Tax Cut (too bad!),” the president tweeted. “It would be great for workers. The Republicans, therefore, didn’t want to ask for it. Dems, as usual, are hurting the working men and women of our Country!”

But in a concession to the president, as currently proposed the measure would double a tax deduction for business meals from 50 percent to 100 percent, a priority for Trump since at least March, after he reportedly met with several restaurant executives who pitched the idea to him.

It wasn’t entirely clear that provision — made notorious by the proliferation of “three-martini lunches” in the 1980s —would make it into the package, however. “If it’s proposed, I’m opposed to it,” said Senate Finance Chairman Charles E. Grassley, R-Iowa. And Wyden, the committee’s ranking member, called it “another giveaway to big, big interests.”

‘Unserious, unsatisfactory’

Even when a Republican package is finally unveiled, it amounts only to an opening bid for bipartisan negotiations, as GOP lawmakers have readily acknowledged. And as they awaited the legislation Thursday, Democratic leaders made clear they would insist on a major rewrite.

“Even after all this time, it appears the Republican legislative response to COVID is ununified, unserious, unsatisfactory,” said Senate Minority Leader Charles E. Schumer, D-N.Y., at a joint news conference with Speaker Nancy Pelosi, D-Calif.

As they continued to push for their own nearly $3.5 trillion package that House Democrats passed in May, they faulted the GOP for not including money for rental and mortgage assistance, election security, help for ethnic minorities and aid to state and local governments, among other things. Democrats sought about $915 billion in state and local aid alone.

Schumer also criticized the GOP plan to provide unemployment benefits that cover only 70 percent of a worker’s wages. “Republicans want you to take a pay cut of 30 percent or even more,” he said.

And Pelosi said Republicans had wasted two months doing nothing while the pandemic continued to rage across the country. “They didn’t use the pause to prepare and what we’ve seen so far falls very short,” she said. “The delay, the denial have caused deaths.”

Paul M. Krawzak, Doug Sword and Jennifer Shutt contributed to this report.