Washington, D.C ? President Bush will promote a constitutional amendment banning gay marriage on Monday, the eve of a scheduled Senate vote on the cause that is dear to his conservative backers.

The amendment would prohibit states from recognizing same-sex marriages. To become law, the proposal would need two-thirds support in the Senate and House, and then be ratified by at least 38 state legislatures.

It stands little chance of passing the 100-member Senate, where proponents are struggling to get even 50 votes. Several Republicans oppose the measure, and so far only one Democrat – Sen. Ben Nelson, of Nebraska – says he will vote for it.

The Senate Judiciary Committee approved the amendment on May 18 along party lines after a shouting match between a Democrat and the chairman, Sen. Arlen Specter, R-Pa. He bid Sen. Russ Feingold, D-Wis., “good riddance” after Feingold declared his opposition to the amendment and his intention to leave the meeting.

Bush aides said he would be making his remarks on the subject Monday.