A federal judge in California said Thursday that the U.S. military's ban on openly gay service members violates the Constitution, the most recent in a string of court rulings overturning restrictions on the rights of the country's gay men and lesbians.

U.S. District Judge Virginia A. Phillips said the government's "don't ask, don't tell" policy is a violation of due process and First Amendment rights. Instead of being necessary for military readiness, she said, the policy has a "direct and deleterious effect" on the armed services.

Citing testimony at a two-week trial in July by experts and former service members, Phillips wrote: "All of these examples demonstrate that the act's restrictions on speech not only are broader than reasonably necessary to protect the government's substantial interests, but also actually serve to impede military readiness and unit cohesion rather than further these goals."

She granted a request for an injunction to stop the military from discharging openly gay service members, but allowed the government time to appeal the ruling.

Phillips's decision is likely to put more pressure on Congress to act on pending legislation that would repeal the policy, which forbids the military to ask about a service member's sexual orientation but retains a ban on gays serving openly. The House voted in May to repeal the act, but the legislation is stalled in the Senate.

Meanwhile, even though President Obama supports the repeal, his Justice Department defended the law before Phillips. Defense Secretary Robert M. Gates has said he believes Congress should not implement a repeal until the military first completes a study on how to integrate gay men and lesbians into the ranks.

The ruling comes just over a month after U.S. District Judge Vaughn R. Walker in San Francisco said a California's voter-approved ban on same-sex marriage was unconstitutional.

And earlier this summer, a judge in Boston said the federal Defense of Marriage Act violated the Constitution. The act denies federal benefits to same-sex couples even in states where their marriages are legal.

All the decisions will begin working their way through the federal appeals court system.

It is expected that the Supreme Court at some point will be called upon to decide the same-sex marriage issues. But "don't ask, don't tell" might be disposed of through the political process.

"It could well be the catalyst that is needed to drop some of the opposition we've seen in the Senate" to holding a vote, said Aubrey Sarvis, executive director of the Servicemembers Legal Defense Network, a group that has been lobbying Congress to end "don't ask, don't tell."

"This should not linger in the courts. It should be resolved by Congress, this year," Sarvis said.