WASHINGTON — With remarkable speed and near unanimity — excepting two Utah congressmen and six of their House colleagues — Congress on Thursday passed legislation intended to ensure consumers can block many unwanted telemarketing calls.

But whether the service millions of Americans signed up for takes effect next week was again thrown into doubt when a second federal judge ruled the list violates free-speech protections. U.S. District Judge Edward W. Nottingham in Denver blocked the list late Thursday, handing another victory to telemarketers, who argue the national registry is unconstitutional and will devastate their industry.

His ruling came shortly after the House and Senate voted overwhelmingly — 412-8 in the House, 95-0 in the Senate — for a bill making clear that the Federal Trade Commission has the power to enforce the "do-not-call" list. The legislation was prompted by an earlier ruling by U.S. District Judge Lee R. West in Oklahoma City who said the FTC lacked the power to create and operate the registry.

President Bush said he looks forward to signing it. "Unwanted telemarketing calls are intrusive, annoying and all too common," he said in a statement.

Two of the tiny opposition minority in the House are Reps. Rob Bishop and Chris Cannon, both R-Utah. Utah's third House member, Democrat Jim Matheson, voted for the bill, as did Sens. Orrin Hatch and Bob Bennett, both R-Utah, for the Senate version.

"I know that likely will be unpopular," Bishop said of his vote. "But I think it's the right thing to do. The bill doesn't ban all calls, just some. For example, it doesn't ban calls from politicians. It's hypocritical for Congress to block other calls but not its own."

He also voted against the original legislation that created the list earlier this year.

Cannon switched positions to oppose it this time, and the reason was unclear. He flew to Utah shortly after the vote, and his staff could not immediately offer explanations for his vote.

Both the House and the Senate measures are intended to more clearly give the Federal Trade Commission authority to impose the no-call list as scheduled next week. West ruled this week that the FTC lacked that authority.

Bishop said he knows the idea of a no-call list is popular with most people — Americans have placed more than 51 million phone numbers on it — but he still feels it improperly interferes with freedom of speech, a point also cited Thursday by the federal judge in Denver.