Britain's biggest trade union gives £11m to Labour but tells Brown: 'There must be change at highest level'

A trade union that has given £11million to Labour has called for change at the 'highest level' of Government.

Senior officials from Unite, the biggest trade union in Britain, made the demand during a top-level meeting with Gordon Brown.

The threat to the Prime Minister was issued by union chiefs Derek Simpson and Tony Woodley, amid concerns over his calamitous collapse in the opinion polls which has left Labour trailing the Tories by more than 20 points.

Mr Brown has angered workers' leaders by rejecting calls for a 50p top rate of
tax and a loosening of strike legislation.

But Unite, which was formed through a merger of the Transport and General Workers Union and Amicus, who have injected such large sums into Labour to save the party from bankruptcy, want a sympathetic ear.

A leaked document, written in the wake of Labour's disastrous by-election defeat to the Tories in Crewe and Nantwich, said: 'The union's concern about the political direction of the Government, as well as the industrial concerns over continued calls for pay restraint in the public and private sectors while inflation busts through the Government's targets, have been put directly to Gordon Brown.

'They have been repeated across the media so our members should be in no doubt the Unite is making the case for change at the highest level.'

The union's warning will concern Mr Brown's supporters who will need their backing if there is a leadership challenge this autumn.

Chris Grayling, senior Conservative frontbencher, said: 'The leadership of the trade unions are putting a gun to Gordon Brown's head.'