London mayor Ken Livingstone yesterday claimed "a victory for democracy and common sense" after the High Court cleared him of bringing his office into disrepute by making a Nazi jibe against a Jewish reporter.

A judge said Mr Livingstone’s remark while "off duty" was "unnecessarily offensive" and "indefensible", and he should have apologised.

But the judge added that "the right to freedom of speech does extend to abuse" and "flamboyant, eccentric characters" in local government should not be penalised for such off-duty behaviour.

The judge ruled the Adjudication Panel for England had misdirected itself in February when it found the mayor breached the Greater London Authority code of conduct by likening Evening Standard journalist Oliver Finegold to a concentration camp guard

The decision to suspend the mayor for four weeks for his remarks was also declared "clearly wrong".

The judge set aside the finding that Mr Livingstone had failed to comply with the code of conduct and formally quashed the suspension.

Angie Bray, leader of the London Assembly Conservatives, claimed the legal victory for the mayor had left the Standards Board for England "toothless".

The Board’s ethical standards officer had referred the Livingstone case to the adjudication panel and must now pay all the mayor’s High Court costs after attempting to defend its decision.

The ESO was refused permission to appeal, but is considering whether to ask the court of appeal direct to hear the case.

The decision was a relief to Mr Livingstone, who warned that if he lost the case he could face bankruptcy, having spent #250,000 contesting the suspension.

Mr Livingstone became embroiled in the legal row after he was approached, while off duty, by Mr Finegold, who was "doorstepping" a reception at City Hall in February last year marking 20 years since former culture secretary Chris Smith became Britain’s first openly-gay MP.