On Wednesday 20 June, the conference of the public services union Unison voted about three to one to endorse an "economic, cultural, academic, and sporting boycott of Israel".

That we won a quarter of the conference against the boycott, from a standing start - the union's Executive unanimously endorsed the boycott motion, and the Unison United Left backed it too - was an achievement.

Still, the boycotters got away with presenting themselves as the people proposing something practical to help the Palestinians - though Helen Jenner, speaking for the union Executive recommendation, stated that she did not interpret the motion as mandating Unison itself to operate a boycott (and so it committed the union to nothing practical at all).

They got away with presenting themselves as the people calling for effective pressure to win the Palestinians the right to a state of their own - though one of the speakers for the motion, from Birmingham Unison, explicitly endorsed Hamas. (Ismail Haniyeh, the Hamas ex-prime-minister, told the Guardian on 18 June [1] that "we want the creation of a Palestinian state on the 1967 borders, that is Gaza and the West Bank, with East Jerusalem as its capital" - but there is really no reason to suppose that this is other than a negotiating stance on the way to the declared aim of Hamas, "to raise the banner of Allah over every inch of Palestine" [2]).

With just a few short speeches on each side, I'm not sure how clearly the fact came across to the majority of delegates that the gist of the motion was not to commit Unison to anything, but to give licence and encouragement to the ardent boycotters, the sort of "smash Israel" enthusiasts who picket Marks and Spencers and who in the 1980s banned student Jewish societies that would not formally condemn "Zionism".

None of the five anti-boycott speakers - Anita Downs (AWL) from Guy's and St Thomas's; Dave Bennett from Bristol Unison (ex-SWP, and now associated with Engage [3]active boycotters).

Stalinoid influence in Unison would have had something to do with it, too. The debate immediately before the boycott one saw a motion on Cuba, uncritically supporting the Cuban government, passed with only a handful of votes against. The CPB (Morning Star) put out a leaflet supporting the boycott and specifically advocating it include a boycott of the Israeli trade unions.

Unison nominally endorsed the "Enough"/ Palestine Solidarity Campaign demonstration on 9 June. It mobilised hardly any members for it. Unsurprising: it is - and rightly so - impossible to recruit any number of democratic-minded working-class people to the slippery slogans and pro-Hamas tone of that demonstration (its high point was a video-cast of Ismail Haniyeh, in which he declared "two states" was not a possibility).

And, of course, if the Israeli right can "show" Israelis that all the active critics of Israeli government policy are supporters of Hamas, then the right will prevail in Israel.

The motion does nothing to break that vicious circle. On the contrary, it makes it worse. It signifies Unison doing "solidarity with the Palestinians" without committing itself to any action. Instead, it has licensed, and "contracted out" solidarity to, the ardent "smash Israel" boycotters - while preserving "deniability" for itself.

Solidarity should be brought back "in house"! Unison and other unions should be mobilising members on demonstrations, pickets, solidarity contingents, and speaking tours, on the clear basis of the union's own declared policy of "two states".

Not wishy-washy even-handedness, but not backhanded support for Hamas or denial of the Israeli Jews' right to a state, either.

The job now is to put this clear solidarity message on the agenda in Unison and other unions, and stop the boycotters setting the terms of debate.