LABOUR could lose up to £40 million between every election if the Trade Union Bill becomes law, GMB general secretary Paul Kenny warned yesterday.

Labour bosses are braced for a £6m fall in trade union funding when an opt-in system to the political levy is imposed on unions by the Tories.

The knock-on effect to Labour funding would force the party to reduce its number of staff and relocate to cheaper offices, according to an internal document leaked to the Guardian.