The Boston labor lawyer who negotiated a controversial $100 million settlement on behalf of Uber drivers is responding forcefully to critics of the deal, saying drivers risk getting nothing if their lawsuits seeking benefits, higher pay, and job protections go to trial.

“If this settlement is scuttled, there is no guarantee that Uber drivers will get anything,’’ Shannon Liss-Riordan, the attorney, wrote in a response to objections that was filed Friday in federal court in San Francisco. “Plaintiffs negotiated the best deal possible that would result in fair monetary and non-monetary benefits to’’ drivers.

Liss-Riordan represented Uber drivers in Massachusetts and California who sued the ride-hailing company for misclassifying them as independent contractors, a policy they said illegally denied them the pay, benefits, and protections afforded to full employees. But in April, looming legal hurdles — in particular, an imminent court ruling that could have knocked thousands of drivers out of the case — prompted Liss-Riordan to work out a settlement with Uber rather than risk defeat at trial.

Under that settlement, which must still be approved by a federal judge in California, Uber would pay $84 million to drivers — $100 million if the company eventually goes public — in proportion to how many miles each drove. The company also agreed to “deactivate’’ drivers only for violating specific clauses in a new driver policy, to allow deactivated drivers to appeal the decision, to stop suggesting to passengers that tips are included in Uber fares, and to meet quarterly with union-like “Drivers Associations.’’

Liss-Riordan has said she will apply to the court to receive 25 percent of the settlement amount as her fee.

A number of Uber drivers — including, embarrassingly, the initial plaintiff in Liss-Riordan’s case — expressed dismay at the deal. Many are angry they will still have to pay for their own gas and other expenses, while not receiving any wages for the time they spend waiting for fares.

Some drivers also want more money than the $4,000 to $8,000 payouts frequent drivers would receive under the deal; others complained that the language of the pact allows Uber to continue deactivating drivers for any reason as long as it provides a written explanation.

“I feel the proposed amount offers drivers 10% of what they are entitled to,’’ an Uber driver named Gary Teitelbaum wrote in a submission to the court. “More worrisome, it fails to address, in any meaningful way, Uber’s ongoing unethical and illegal treatment of drivers. . . Seems this settlement is a boon only to Uber, who is getting off easy, and Ms. Riordan, who is getting rich while leaving [drivers’] situation not improved in any meaningful way.’’

As a result, attorneys for some Uber drivers have filed objections to the settlement, or sought to replace Liss-Riordan as leader of the class-action lawsuits. They argued Uber made few meaningful nonmonetary concessions, and that even those will expire in two years. The settlement also conceded the central claim of the lawsuits too easily, they argued, allowing Uber to continue classifying its drivers as independent contractors and not employees. “The court should not be fooled,’’ an attorney for Los Angeles driver Steven Price wrote in a recent filing. “There is no real ‘change’ in the proposed settlement.’’

But in asking a judge to approve the agreement, Liss-Riordan said Price and other critics were a vocal minority and had not carefully weighed the concessions offered by Uber against the risk of a trial. She blasted attorneys who filed objections as opportunistic, calling one a “celebrity lawyer’’ and suggesting the rest lacked her expertise. “Notably, some of the loudest objections come from lawyers who do not practice in this field,’’ Liss-Riordan wrote. “These lawyers have jumped into the fray to second guess [my] careful decision-making. . . . These same attorneys would have settled for a fraction of this amount were they given the opportunity, and . . . Uber drivers are tremendously fortunate to have experienced counsel negotiating on their behalves.’’

Uber declined to comment. But in a recent filing, the company joined Liss-Riordan in defending the settlement, calling it “a compelling and eminently reasonable deal that is entitled to preliminary approval.’’

The company’s attorneys said the objections were “largely irrelevant’’ and called the suggestion by some objectors that they had colluded with Liss-Riordan “laughable,’’ given the “hotly contested’’ proceedings before the settlement. They also noted that only about 30 drivers filed objections, out of a potential class of 380,000.

Dan Adams can be reached at dadams@globe.com. Follow him on Twitter @DanielAdams86.