Britain’s biggest trade union Unite, has confirmed it will be backing a boycott of Israeli goods proposed by the Fire Brigades Union, along with public sector trade union, Unison.

Unison and Unite’s support will now make the FBU’s chance of successfully getting the TUC to agree to the motion far greater.

Motion 76, tabled by the firefighters, called for the TUC to review its links with Histadrut, its Israeli trade union counterpart.

It also called for a ban on the importation of all goods from “illegal settlements”, the ending of all arms trading with Israel, a boycott of Israeli goods and divestment from companies “associated with the occupation”.

The motion will be debated at the TUC tomorrow in Liverpool.

The GMB, which proposed a compromise amendment condemning Hamas as well as Israel took the unusual step of issuing a statement condemning the actions of fellow trade unions.

Paul Kenny, general secretary of GMB said: “GMB is not a gesture trade union and we do not believe in carrying motions that we do not intend to put into effect. GMB does not believe that the position set out in Motion 76 is the correct position.

“GMB has no mandate for it and we believe it would cut off lines of communication with the Israeli trade unions. We will be moving our amendment to the floor tomorrow and we hope we will persuade the Congress to adopt what we consider is the correct position on this motion.”

GMB will support continuing links with Histadrut.

The FBU cited Histadrut’s support for the recent conflict Gaza as the reason for its proposed review of the two trade unions’ relations.

When the amendment was first proposed, a spokesman for the FBU said: “The Fire Brigades Union is proud of our history of opposition to racism. Our motions to the TUC are in that tradition of international concern.

“We are aware that there are progressive elements in Israeli society who strive for peaceful coexistence with the Palestinians and the establishment of a sovereign Palestinian state. Our TUC motions aim to strengthen that movement towards peace."