Contra aid issue bounces back onto the congressional agenda. Conservatives push proposals including military equipment

Nicaraguan troops have withdrawn from Honduras. The antagonists in Nicaragua's seven-year-old civil war are negotiating a cease-fire. But the United States Congress is still tying itself in knots as it attempts to decide whether to extend new support to Nicaragua's US-backed contra rebels.

The latest push for aid began last week, after Nicaraguan troops crossed the Honduran border in an effort to ambush contra encampments. But it has not subsided since the Sandinista forces retreated behind Nicaragua's borders.

Though the contras and Sandinistas have agreed to a temporary cease-fire and have, for the first time, initiated face-to-face negotiations toward a permanent truce, conservatives in the House of Representatives and the Senate are readying proposals to provide fresh infusions of basic supplies and military equipment to the rebels. (Cease-fire talks: Page 11.)

``It's important that military pressure is brought to bear to keep the negotiations on track,'' says House minority leader Robert Michel (R) of Illinois. ``Events of the past week show you can't put faith in [Nicaraguan President Daniel] Ortega.''

At a Capitol Hill meeting yesterday, President Reagan admonished House Republicans that the threat posed by the Sandinistas to Central America ``won't go away'' if Congress refuses to grant new aid to the rebels. But the President was speaking to an audience that hardly needed convincing.

Still to be persuaded, however, is the House Democratic leadership, without whose approval a floor vote on any contra aid proposal is unlikely.

Speaker of the House Jim Wright (D) of Texas sustained an embarrassing defeat earlier this month when Republicans joined conservative Democrats to vote en masse against a contra aid package crafted by moderate and liberal Democrats.

After that incident, Democratic leaders expressed defiance toward the contra supporters who opposed their package, asserting that any new contra aid proposal would have to pass through the lengthy committee process.

But events of the past week clearly put the Democratic leadership on the defensive. Now, Speaker Wright indicates he would allow another vote on a package granting the contras food, clothing, medicine, and communications equipment - a combination essentially identical to the earlier Democratic proposal conservatives dismissed as inadequate.

``If [the Republicans] were interested in moving a bill which would provide humanitarian aid, we would work with them,'' says Wright. ``We're still ready.''

Yet conservatives, emboldened by the negative impact in the US of the Sandinista foray into Honduras, vow to oppose such a package as they did before. ``You can't fight helicopter gunships with Spam,'' says Rep. Robert Walker (R) of Pennsylvania.

So the conservatives are crafting contra aid proposals of their own in the hope that the House leadership can be persuaded, or embarrassed by Sandinista behavior, into allowing them a vote on the House floor.

Senate conservatives have a similarly uncertain strategy. Liberal senators opposed to contra aid may launch a filibuster against the conservative proposal. It is considered unlikely that the 60 votes needed to shut down a filibuster can be found.

Sen. David Boren (D) of Oklahoma and a handful of contra supporters in the Senate have crafted a plan that would grant $48 million in new, non-military aid to the contras, along with authority for Reagan to resume deliveries of $2 million to $5 million in military supplies that were bought in 1987. The Senate package would also require Congress to vote again on a contra aid package of the President's design.

In the House, a group of six Democrats led by Rep. Buddy MacKay (D) of Florida has defied Wright's request and introduced an identical proposal, excluding the guarantee of another vote.

Meanwhile, a group of House Republicans has drafted a plan that would provide $90 million in military and non-military aid for the next 12 months.