SOCIALIST PARTY members should stand down as candidates in “the 100 Labour must-win marginals,” general union Unite’s broad left caucus said yesterday.

In an open letter to SP activists, members of Unite’s United Left said standing against Labour in its target seats “where every vote counts” would amount to “a breach in a working-class front against the Tories” and rob Labour of a majority.

Signatories to the letter include Unite executive council chair Tony Woodhouse and Labour NEC member Martin Mayer.

The Socialist Party is taking part in May’s general election as part of the Trade Unionist and Socialist Coalition (Tusc), which is aiming to stand 100 candidates.

The letter, which doesn’t attack any other left-of-Labour parties standing in May, accuses Tusc of having a “derisory” electoral record, accusing it of aiming only “to recruit and make propaganda.”

It accuses the SP of “blind sectarianism” for believing that there is “no difference between Labour and the other capitalist parties.”

The SP hit back at the call to support a government that “would be at best austerity-lite and a continuation of the srisis that faces working-class people.”

Pointing out that Tusc had canvassed Labour candidates on their opposition to the cuts and other policies before deciding to stand, the lengthy letter said: The tragedy is that the Labour-affiliated unions haven’t challenged Labour on the cuts. The fact that the election result is in the balance is a condemnation of Labour.”

The issue will be raised at tomorrow’s meeting of the United Left in Birmingham.