President Carter suffered another defeat in Congress yesterday when a House subcommittee voted to postpone action indefinitely on a key section of his urban program.

The 7-to-6 vote by the House intergovernmental relations subcommittee came on a measure that would have provided economically distressed cities with $2 billion in aid over two years. The whole episode lasted 45 minutes.

When it was over, the were many red faces, much backbiting and fear that Carter's program would now just bleed to death.

The vote itself was not a surprise. Last week, subcommittee Democrats voted 5 to 3 against the bill. But what angered the measure's supporters was the way yesterday's vote was handled and the way the White House worked - or failed to work, according to some sources - in behalf of the legislation.

"It's sad that people are pointing fingers at each other over this thing, but we have questioned the White House's strategy since day one," said Tom Cochran deputy director of the United States Conference of Mayors, which is lobbying for antirecession aid to hard-pressed cities.

"The White House has insisted on trying to get this thing through the subcommittee against our wishes . . . This subcommittee has always been against (antirecession) legislation. We thought our best more would have been to work through the Senate."

He said such legislation has usually fared better there because of support from people such as Sen. Edmund S. Muskie (D-Maine) and Majority Leader Robert C. Byrd (D-W. Va.) "They were key in getting the bill through last year," Cochran said.

Cochran declined to comment on why he though the White House continued to try to push the urban aid measure through the 13-member House subcommittee despite intense opposition there. White House urban policy officials declined to comment until they had a chance to check with "our people on the Hill."

But their reticence was not matched by Rep. Les Aspin (D-Wis.), behaved in an "exremely insulting and inexcusable manner" by severely limiting debate on the measure. On one occasion, for example, Fountain gave a subcommittee member five seconds in which to speak.

Aspin accused Fountain of railroading yesterday's vote by eliminating opportunities to amend the legislation.

Fountain, during the subcommittee meeting disagreed saying it was a simple matter. "All of the overwhelming evidence is that this bill is a wholly inequitable and unacceptable" measure, he said. The legislation, he said, would aid rich cities as much as it would aid poor ones, and that there really wasn't much to talk about.

Fountain said the bill should be put aside until next year.

However, Aspin, Cochran and other supporters of anti-recession aid said they will try to get a bill passed before Congress begins its Labor Day recess.

One plan is to bring at least 30 big-city mayors to Capitol Hill to plead their case while working in the Senate to get an antirecession bill out of that chamber and before a more favorable House committee.