House Republicans yesterday accused House Speaker Jim Wright (D-Tex.) of reneging on his commitment to permit the House to vote on a GOP package of aid to the Nicaraguan contras, charging that Thursday's debate on the issue has been structured in a way that favors passage of the Democrats' plan for humanitarian aid.

"Seldom in my tenure in Congress has the Democratic majority exercised such abuse of the legislative process as they have in the procedures which have been forced upon us for considering the speaker's contra-aid proposal," said House Minority Leader Robert H. Michel (R-Ill.) in a prepared statement.

Working through the Rules Committee that it controls, the Democratic leadership yesterday established ground rules for House consideration of contra aid that forces the House to vote first on the Democratic plan. Only if that proposal for $30 million in strictly humanitarian aid is defeated would the House have an opportunity to vote on a Republican plan that would provide $36 million, including a continuation of some "nonlethal" logistical support for the rebels and continued deliveries through the Central Intelligence Agency.

Republicans immediately charged that the seldom-used procedural gambit effectively ensures passage of the Democratic plan, which Wright promised to Democratic moderates shortly before the House on Feb. 3 defeated President Reagan's package of contra aid that included some direct military assistance.

"The practical effect is it greatly increases their vote," said Rep. Mickey Edwards (R-Okla.), a leading House supporter of the Reagan administration's policy of aiding the rebels fighting the Marxist Sandinista government. "What they've done is totally violate the understanding with us that we would get a vote . . . . They've broken faith with us."

Several times in the past week Wright has said that the House minority would have an opportunity to have its contra-aid plan voted on. Last Thursday, for example, when asked about the displeasure of some liberal Democrats with that pledge, Wright said, "I don't think you win by denying other people" a vote on the Republican plan.

Republicans were particularly outraged by the Democratic leadership's action because it followed by only a few weeks an effort by Wright to patch up his relationship with the minority after a contentious 1987 session during which Republicans said they felt he had repeatedly trampled on their rights.

"I don't think they're in a position to complain they're being mistreated," Wright spokesman Wilson Morris said yesterday. "There are two proposals on the floor, and ours will be voted on first. The other option would be to go the other way around. If it's unfair to them, would it have been unfair to us?"