A councillor who dismissed residents’ complaints about a company with links to Israel has lost an independent investigation into the case.

Former Barnet mayor Brian Coleman said that concerns about waste management company Veolia’s involvement with the North London Waste Authority were “anti-Israel nonsense”.

Mr Coleman, a member of Conservative Friends of Israel and a former London Assembly member, told one resident who complained: “I suppose 70 years ago you would have been in the blackshirts.”

He was found to have broken local authority conduct rules on respect in March but appealed to an independent Local Government Standards tribunal which reinvestigated the claims against him.

Anti-Israel activists have regularly targeted French firm Veolia over its links to the Jerusalem light rail project.

Mr Coleman had replied to the residents in his then position as environment portfolio holder at the council. When one of the complaintants replied saying he was Israeli, Mr Coleman told him he was “disloyal” and had been “flushed out”.

But the independent tribunal rejected Mr Coleman’s appeal, ruling that the council had been “fair and proportionate” in its sanctions. It ordered him to apologise in writing to the residents.

Mr Coleman has until early September to appeal the tribunal’s finding. He said he did not intend to apologise.