The commissioner for public appointments is to investigate primary care trust board appointments, following renewed allegations that Labour is filling boards with its cronies.

Figures revealed in Parliament showed almost four times as many PCT chairs declare political activity for the Labour Party compared to those favouring the Conservative and Liberal Democrat parties.

The accusation comes just eight months after a scathing report from the public appointments watchdog on appointments to trust and health authority boards charged: 'The process has become politicised in a systemic way.'

In a letter to Conservative MP Graham Brady, commissioner for public appointments Dame Rennie Fritchie says the new figures revealed in a parliamentary written answer are 'indeed worrying in the context of the findings of the scrutiny'.

Figures issued by junior health minister Gisela Stuart in response to questions from Mr Brady show that 26 per cent of PCT chairs have declared political activity with the Labour Party, compared with 7 per cent each for the Conservatives and Liberal Democrats.

Among non-executive directors, 22 per cent declare political activity with Labour, 5 per cent with the Conservatives and 4 per cent with the Liberal Democrats. Two-thirds of nonexecutives and 56 per cent of chairs declared no political activity.

Mr Brady accused the government of 'essentially ignoring' the commissioner's report. And he said the new appointments system promised in the NHS plan would not be enough to resolve the problem.

From April, a new NHS appointments commission, with a chair and eight members covering the NHS regions, will make all non-executive appointments.

But Mr Brady said: 'The big flaw is that while they may say It is an independent panel, it will itself be appointed by the secretary of state.' And he added: 'The evidence from PCT appointments is they're trying to stuff as many political activists in as possible before the new rules take effect.'

NHS Alliance chief executive Michael Sobanja said: 'We want the best people for the job, regardless of political affiliation, race, religion or anything else.'

National Association for Primary Care chief executive Clive Parr said any such problems should be looked at, but added: 'I can't cross my heart and say the phone is red-hot with people ringing up about it.'

'One or two members of staff ' from Dame Rennie's office will review a sample of PCT appointments drawn from across all the NHS regions by 31 March. The findings will be published in July.