Opponents of the Brookline-Elm route of the Inner Belt have begun a last-ditch campaign to get the Federal Bureau of Public Roads to override the state's choice of the route.

"We have lost a battle -- a very big battle -- at the state level, but we have not lost the war," the Rev. Edward J. McManus, chairman of a citizens' committee opposed to Brookline-Elm, told an audience of 150 in St. Mary's auditorium last night.

The State Department of Public Works announced last Friday that it had definitely chosen the Brookline-Elm route -- a path which will uproot at least 1200 families. The route must still receive final approval from the federal bureau, which will pay 90 per cent of the cost.

The Bureau seldom overrides a state reccommendation, but the Belt foes hope to convince them that the state failed to comply with a provision of the 1962 Highway Act. The provision requires states to consult local residents when planning highway routes.

Some 100 opponents of Brookline-Elm plan to picket the Washington office of the Bureau next Tuesday, dressed in black to dramatize the "death of the future of Cambridge."

Cambridge Mayor Daniel J. Hayes Jr. announced that the City Council will itself go to Washington on June 14 to meet with Federal officials. He said that the councillors would attempt to "discuss and persuade," but supported the more direct efforts of the picketers.

It is possible that Sen. Edward M. Kennedy '54 (D-Mass.) will come to Cambridge Saturday to hear the case of the Brookline foes.