Left-wingers have failed to get rebel MP George Galloway reinstated to Labour as the party's ruling board met on Tuesday.
Galloway was suspended over his anti-war comments
Labour's general secretary, David Triesman, said the fate of the maverick MP, suspended by the party over the Iraq war would be decided "relatively quickly".
Mr Triesman insisted the inquiry into Mr Galloway's remarks would not be allowed to drag on so the MP was barred automatically when Labour chose its election candidates in Glasgow.
Labour's deputy general secretary, Chris Lennie, is investigating whether Mr Galloway tried to incite Arab armies to fight British troops in Iraq.
In March, the MP told Abu Dhabi television: "Even if it is not realistic to ask a non-Iraqi army to come to defend Iraq, we see Arab regimes pumping oil for the countries who are attacking it.
For myself, I stand by every word I said before the war, during the war and since the war
"We wonder when the Arab leaders will wake up. When are they going to stand by the Iraqi people?"
At Tuesday's meeting of Labour's National Executive Council, Tribune editor Mark Seddon and a few others said the way Mr Galloway was being investigated breached party rules.
again refused to change its mind and Mr Galloway remains in "administrative
Glasgow Labour members will start choosing candidates after the party's autumn conference, with Mr Galloway's seat among three being merged into two constituencies.
Mr Triesman said: "What I know about the pace of the investigation means it should be cleared
up long before that."
Mr Galloway is currently barred from representing Labour in any way but says he will stand as an independent if Labour tries to stop his selection.
He continues to say he will contest a libel action against the Daily Telegraph over suggestions he took money from the Iraqi regime.
The MP was cheered by supporters as he arrived to protest his case outside the NEC meeting in London.
He said: "The national executive is going to be left in no doubt that the movement in the country has not gone away, that it cannot silence its voices and that it maintains its opposition to the war and the occupation of Iraq.
"For myself, I stand by every word I said before the war, during the war and since the war.
"Moreover, what we said as an anti-war movement is daily being vindicated, indeed more spectacularly, more swiftly even than we predicted."