A day after he confronted the Senate’s top leader about the city’s plight during the federal shutdown, Mayor Vincent C. Gray told a crowd of hundreds that the impasse threatens the city’s education, transportation and health care systems and called on residents to press Congress for an exemption.

“For us, it’s not a game,” Gray said. “It has deadly serious consequences for thousands, thousands of our most vulnerable residents.”

Gray’s address, delivered at the Friendship charter school campus near Barney Circle in Southeast, concluded in a standing ovation and the mayor pumping his fist, leading chants of “Free D.C.”

On Wednesday, Gray led a news conference on the Capitol grounds that morphed into an unusual chance encounter with Senate Democrats, who were holding a news conference of their own just yards away. In front of reporters, Gray pressed Majority Leader Harry Reid (Nev.) to pass a bill that would exempt the city from the 10-day-old shutdown, making the case that the city deserves to spend its locally raised funds even while the federal situation remains unresolved.

Reid — who has maintained a position, shared by President Obama, against passing piecemeal funding bills — responded: “I’m on your side. Don’t screw it up, okay?”

Where U.S. is feeling the shutdown

Where U.S. is feeling the shutdown

Read about people's experiences with the shutdown across the nation.

In an interview after the address, Gray said he spoke with Reid later in the day, having a “very cordial” exchange. But he said Reid showed no indication of abandoning his strategy, and the call ended without any concrete commitments.

“We just had a conversation,” he said.

City employees remain on the job, thanks to a $144 million contingency reserve fund, but the city is conserving its cash by skipping many of its bills. Gray said Thursday it remained unclear what might happen after the fund expires, but said for the first time he would not take employees off the job under any circumstances: “I am not furloughing anybody.”

But Gray said in his address that he would not break federal law to keep the city running, brushing back suggestions from some D.C. Council members and activists that he simply spend the city’s money without authorization.

“For starters, it undermines our moral authority as we make the case to Congress that we deserve to be permanently freed from being forced to ask permission to spend our own money,” he said. “It hurts our case that we are responsible stewards, ready to control our own fiscal destiny.”

Gray also said that while he was personally willing to engage in civil disobedience, other city workers would be at risk of prosecution. “It’s not right for me to put our employees in legal jeopardy,” he said.

In the alternative, he said, city lawyers are “exhausting every legal means at our disposal to identify as many resources as possible and to stretch them as far as we can.”

In the speech, Gray highlighted impacts to various city services -- including an already-missed payment to Metro, frozen Medicaid payments that have led some health care providers to cut back services, and the potential for a devastating missed payment to the city’s 60 charter schools.

The federal shutdown — which affects the city’s ability to spend its locally raised funds, including sales and property taxes, in addition to federal funds — has affected other service providers as well.

Sasha Bruce Youthwork, a well-regarded nonprofit that serves hundreds of city youths, said Thursday it would furlough 46 full-time staffers and put another six on part-time status due to the uncertainty of its funding streams.

Executive Director Deborah Shore said the organization chose to conserve funds by prioritizing its housing programs for homeless and runaway youth by suspending community based programs, including in-school programs and AIDS prevention work. “We took a look at this picture and said we need to get ahead of this,” she said.

Shore said the organization has “tapped everything” in a bid to preserve services: “We have some cushion, but ... we’re on shaky ground here and we can’t be guaranteed that we’ll be able to recoup all of these funds. So we had to make some decisions.”

Aaron C. Davis contributed to this report.

This report has been updated.