Former chancellor of the Exchequer Denis Healey and former House of Commons leader Michael Foot tonight won the right to face each other in a runoff election by Labor Party members of Parliament for the leadership of Britain's ideologically divided opposition party.

Healey, the candidate of the right wing of the labor union-based party that created Britain's welfare state, took an expected lead on today's first ballot by 265 participating Labor members of Parliament. He won 112 votes to 83 for Foot, who is supported by the party's more radically socialist left wing in this stage of what promises to be an uncertain and drawn-out leadership selection process.

Two other candidates, former agriculture minister Sam silkin and the party's foreign affairs spokesman, Peter Shore, won 38 and 32 votes respectively in today's first ballot. They were forced out of the race because their combined total was less than Foot's.

The runoff between Healey, 63, and Foot, 67, is to end in a second ballot by next Monday after intensive lobbying for the votes of Silkin and Shore supporters. The winner then may face a new test next year -- another leadership election by a proposed electoral college representing Labor members of Parliament, trade unions and party constituency organizations, if the college can be established by a party conference in January.

Healey, who supports Britain's mixed welfare state economy and active membership in the North Atlantic alliance and the European Common Market, is expected to have a difficult time winning undisputed party leadership despite his 29-vote lead in tonight's first ballot.

Foot, an ardent campaigner for nuclear disarmament, can count on the votes of many left-leaning supporters of Silkin and Shore, who both favor pulling Britain out of the Common Market but not NATO. He also is expected to pick up some support from centrists who believe he is more likely than the pugnacious Healey to hold the embattled party together until it can reach a consensus on new processes for leadership election and parliamentary candidate selection and new economic, defense and foreign affairs policies.

The party's insurgent left wing, which has captured control of much of its grass roots organization and union leadership, wants to offer more radical socialist and isolationist alternatives to the right-wing conservative government of Prime Minister Margaret Thatcher. Left-wing-controlled Labor constituency organizations are strongly pressuring their legislators to vote for Foot.

But these groups favor the leader of the left-wing grass-roots movement, former energy minister Tony Benn, in the electoral college contest next year. fBenn, who bypassed leadership selection by Labor members of Parliament, has announced he will be a candidate in the electoral college.

If Foot is selected as leader now, he is expected to submit himself for ratification by the electoral college, although he has refused to make a public commitment. Healey, however, is believed ready to ignore the electoral college if he is elected now and decides the electoral college is not "at least as democratic" a method for selecting the party leader.

This could leave Labor with both a parliamentary leader, eligible to become prime minister if Labor regains control of Parliament, and a titular party leader. This, or Benn's later election as party leader, could split Labor and further dissipate its already ineffective parliamentary opposition to Thatcher's monetarist economic policies.