ANN ARBOR, Mich., Feb. 7-A national student antiwar conference issued a call here tonight for massive obstructive protests in Washington May 1 in support of the "people's peace treaty" -and for demonstrations across the country this Wednesday to protest the invasion of Laos by South Vietnamese troops.

The call ended a three-day session of the Student and Youth Conference on a People's Peace, which met to discuss actions to support the treaty negotiated by North Vietnamese students and representatives of the National Student Association (NSA).

About 2000 people attending the gathering, organized by NSA, the Midwest Peace Treaty Coordinating Center, and a loose coalition of students at the University of Michigan, which hosted the conference.

Ngueyen Thi Binh, chief negotiator for the Provisional Revolutionary Government of South Vietnam, sent a telegram to the conference today charging that a massive invasion of Laos by U.S., South Vietnamese, and Thai ground troops was in progress and urging the group to mobilize the antiwar movement in protest.

The NSA delegation traveled to North Viet Nam late last year and worked out terms of the "people's peace treaty" with students from North andSouth Vietnam. The treaty has since been approved by the PRG delegation to the Paris peace talks.

Its Terms

It calls for total withdrawal of all U.S. forces from Indochina by a date to be publicly announced, and for an end to U.S. support for the current Saigon government.

The Vietnamese agree to enter discussions to ensure the release of U.S. prisoners and the safety of withdrawing U.S. troops after the date has been set for total withdrawal. They also pledge to form a provisional coalition government and to hold democratic elections in South Vietnam.

Signers of the treaty agree to take "whatever action is necessary to implement [its] terms."

The conference in effect repudiated a call by the Student Mobilization Committee for a non-violent demonstration in Washington April 24.

The conference did not devise a precise scenario for the May demonstration, but there was agreement that some form of obstructive activity should take place in Washington beginning May 3 if the government refuses to agree to the terms of the treaty.