D.C. Mayor Muriel E. Bowser awaits the start of a news conference last month. Last week, she let a bill to give new parents eight weeks off following the birth of a baby pass without signing or vetoing it, even though she had been highly critical of its costs to businesses. (Matt McClain/The Washington Post)

In the first real test of her power in the face of a new left-leaning D.C. Council, Mayor Muriel E. Bowser dodged a showdown over the city’s paid-family-leave bill.

Bowser was opposed to the legislation, among the most generous paid-leave policies in the country, for several reasons. She was concerned about the $250 million annual tax it would impose on employers. She worried that it would benefit city workers who lived in Maryland and Virginia more than her own constituents. And she felt it was imprudent to expand government when the city may face cutbacks under the Trump administration.

The business community, even more opposed to the law, was counting on Bowser to block it.

But Bowser didn’t veto it. And she didn’t sign it, either. She let the bill become law without her signature and then sent a letter to the D.C. Council, maintaining that she had “grave concerns” about it.

The move left business leaders, who had spent weeks lobbying council members to back up a mayoral veto, scratching their heads, and the liberal lawmakers who passed the measure newly emboldened.

Bowser’s inaction drew criticism from both sides.

“She’s out there by herself — completely alone right now — and that’s not a good place to be,” said Jim Dinegar, head of the Greater Washington Board of Trade.

Dinegar, along with the heads of every major business group and associations representing D.C. restaurants, colleges and hospitals, had urged Bowser to veto the “deeply flawed and unnecessarily expensive” bill.

Aides to the mayor said she ran out of time to build consensus around an alternative plan that could get enough votes to sustain a veto.

“To put a veto on it, the mayor knows that doesn’t mean anything unless you have the votes to sustain it,” said a high-ranking aide to the mayor who spoke on the condition of anonymity to discuss Bowser’s decision.

But by not using her veto power, Dineger said the mayor lost the force of argument that she was doing everything she could in the city’s best interests. Dineger was also critical of the business community, saying it should have done more to help Bowser find the votes needed to sustain a veto, since without it “she can’t claim the mantle of fiscal responsibility.”

Bowser (D) also couldn’t win praise from progressives in her own party who have been pushing for family-leave benefits nationwide.

“I’m disappointed she didn’t sign the bill. It’s just the right thing to do,” said council member Elissa Silverman (I-At Large). “I have been hoping the mayor would change her mind and embrace it and work with us. I’m still hoping.”

In a phone interview late last week from New York, where she was attending Jesse L. Jackson’s annual Wall Street Project Economic Summit, the mayor defended her inaction.

Bowser said she was confident that she would still be able to prod the council to improve the law.

“My goal was never to kill paid family leave, but to get a better bill,” Bowser said. “I think this is the best way to get there so we don’t make the next step a veto fight, but work with the council to craft a better bill for D.C. residents and D.C. businesses.”

The new law will take effect in late March barring intervention from Congress.

The D.C. law provides for up to eight weeks of paid time off to new parents, six weeks to workers caring for ailing family members and two weeks of personal sick time. Workers could begin taking the benefit in 2020. To pay for it, the city will levy a new 0.62 percent payroll tax on employers.

Bowser’s decision not to veto the legislation laid bare her diminished power on the council since November, when three of her allies lost their seats to challengers who were openly critical of the mayor.

To sustain a veto, Bowser would have needed five votes, and observers said those would have had to include Ward 8 council member Trayon White (D), who defeated Bowser protege LaRuby May, and former mayor and Bowser nemesis Vincent C. Gray (D-Ward 7).

In separate interviews in the hours before Bowser announced her decision, Gray and White said they support family leave but were open to less-expensive alternatives that would keep more money in the District. Before taking office last month, Gray had said that Bowser would have to personally ask for his vote. Neither Gray nor White said he heard from Bowser directly.

Top aides to the mayor, however, had talked to both and were reporting back to Bowser that there was no certainty she would get five votes.

“The business community is disappointed, and the business community is looking for a champion to get a responsible paid-leave program through the process,” Vincent B. Orange, the Chamber of Commerce’s president and a former D.C. Council member, said Thursday. “Clearly, we may have to look elsewhere for that leadership to really get folks to the table and hammer things out.”

By Friday, it looked like business leaders had found their new champion.

With Bowser still in New York, D.C. Council Chairman Phil Mendelson (D) said he would introduce a new bill in coming weeks to reopen the financing discussion. Although he was the architect of the funding plan in the bill that was approved in December, Mendelson said he believed enacting it would go more smoothly if the business community is supportive.

Mendelson’s bill sounded almost identical to the one quietly proposed last week by several in the business community. But it was unclear how far he would go in supporting the idea.

With the threat of her veto gone, Bowser will also have less clout to negotiate changes.

Authors of the new law said Friday that while they would be open to tweaking how the benefit is funded, they would not accept any reduction in benefits for workers now in the law.

Bryan Weaver, a former council candidate and an Adams Morgan neighborhood activist, said it is hard to envision a politically winning scenario that remains for the mayor.

“The passiveness on this, I think, could come back to haunt her,” Weaver said. “Either you’ve tossed your hands up in the air and are walking away, or you’re just kind of passive and whatever happens in the council happens. Neither one of those, I think, makes her look authoritative as the chief executive of the city.”

Council member Jack Evans (D-Ward 2), a vocal opponent of the bill, said he thinks the mayor could have lined up five votes to sustain a veto if she had simultaneously proposed a viable alternative.

“It would have put the pressure on the council,” he said. “Now it’s just going to go into law.”

Joanna Blotner, campaign manager for the D.C. Paid Family Leave Coalition, said the advocates will push to implement it in its original form. “We certainly can’t take our eyes off the ball,” she said.

Blotner said she also remains hopeful that Bowser can be persuaded to support it.

“Hopefully, this is something that the mayor decides is actually in her interest and that she does want to show leadership on,” she said.