Extreme left-wing socialists have declared their intention of pushing the British Labour Party irrevocably into the Marxist camp and ultimately expelling moderate members.
The challenge to the Labour movement comes from the Militant Tendency, a Marxist group within the party that moderate rank-and-file members want to see ejected from Labour's ranks.
Labour Party leader Michael Foot has supported attempts to declare the Militant Tendency unconstitu--tional for being a party within a party. But at Labour's annual conference later this month it seems unlikely that he will succeed in getting the better of the many Trotskyists who comprise the militant membership.
The challenge to Mr. Foot and his supporters was issued at the Militant Tendency's weekend camp in south Wales at which Trotskyists gather to discuss political tactics.
Ted Grant, a leading member of the Militant Tendency, attacked Mr. Foot's plan to compile a register of organizations affiliated with the Labour Party. Foot wants to ensure that the Militant Tendency is not on the register.
Mr. Grant said that for every member of his group expelled, 10 new Trotskyists would gain admission to the Labour Party.
''The Labour Party itself will become Marxist, the trade unions will become Marxist. Our policy, our approach, will become those of the Labour Party and of the trade union movement,'' Grant declared.
Militant Tendency's political program includes state ownership of the means of production, abolition of the monarchy and the House of Lords, and Britain's withdrawal from NATO.
Labour leader Foot is having to take the group seriously because it has been behind a number of successful attempts to infiltrate local constituency parties and select extreme left-wing parliamentary candidates.
The activities of the Militant Tendency and other left-wing groups was an important factor in the formation of the new Social Democratic Party by moderate senior Labour politicians, among them the SDP leader, Roy Jenkins.
Even if Foot gets his way and the Militant Tendency is deregistered, there will be little to stop militant members remaining in the Labour Party. Indeed the party leader intends to give them a choice of belonging to the Militant Tendency or remaining Labour Party members.