President Reagan asked Congress yesterday to give Jordan $250 million in economic aid as a signal of support for King Hussein's moves toward peace talks with Israel, but congressional sources forecast an overwhelming rejection that could derail hopes for peace in the Middle East.

The response of Republican senators was so cool that it was not clear whether any would be willing to work within the Appropriations Committee to include the funds in a $13.4 billion supplemental money bill that the Senate began considering yesterday.

Sen. Robert W. Kasten Jr. (R-Wis.), chairman of the appropriations subcommittee on foreign operations, said only that detailed briefings, and possibly hearings, would be held on the request next week. Then, Kasten added, senators would have to see "if a necessary consensus has developed" before deciding to push for passage of the funds.

Until now, the Senate has shown little interest in rewarding King Hussein with new economic aid, largely because of widespread sentiment that the king has done too little to advance the Mideast peace process.

His recent peace offensive, including promises that the Palestine Liberation Organization is prepared to let him negotiate on its behalf, has yet to win many converts on Capitol Hill, according to numerous sources there. Israel's friends in the Capitol have encouraged this skepticism.

In making the request for new aid to Jordan, Reagan ignored warnings from Senate Majority Leader Robert J. Dole (R-Kan.) and Foreign Relations Committee Chairman Richard G. Lugar (R-Ind.) that considerable spadework remains before a skeptical Senate can be persuaded to vote for Jordanian aid.

Reagan had agreed to defer temporarily a more controversial plan to sell Jordan advanced weapons worth as much as $750 million. U.S. officials said yesterday that he felt obligated to ask for the economic aid "as a sign to Hussein that he has the president's backing at a time of intensified efforts to find a basis for direct peace talks between Jordan and Israel."

Lugar, while publicly reserving comment, is understood to have warned Secretary of State George P. Shultz that the effort is likely to boomerang and result in a rebuff to Hussein.

Lugar reportedly noted that Reagan also wants funding for Nicaraguan counterrevolutionaries included in the same supplemental appropriation, and he is understood to have said it would be "a legislative miracle" for the administration to get favorable action on both measures in the short time remaining before the Fourth of July congressional recess.

The $250 million economic aid request, which would be spread over two years, would give Jordan $100 million for a commodity import program, $100 million in unrestricted cash aid and $50 million for specific aid projects.