The Trades Union Congress may adopt emergency powers to condemn Israel at its annual conference.
TUC delegates will meet in Liverpool from Saturday. The conference final agenda does not contain any motions relating to Israel and the Palestinians as the height of the Gaza conflict came after the TUC's deadline for motions.
But it is thought a special procedure could be put into effect to enable debate on the conference floor.
The 54 affiliated unions representing more than six million workers issued a statement through their general council in July attacking Operation Protective Edge. It accused Israel of "collective punishment", and urged the government to impose an arms embargo. The statement did not include any references to Hamas or its rockets.
Trade Union Friends of Israel will run a stall at the conference and is due to hold a fringe event on Tuesday. It will come shortly before a session organised by the Palestine Solidarity Campaign. Tufi director Steve Scott said: "I can't see the issue of Israel not coming up."
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