Tony Blair's ministers make 'impossible' demands, it is claimed

Lord Wilson of Dinton said people were worried about "decisions being taken without formal processes".

Another former cabinet secretary, Lord Butler, said ministers had asked civil servants to perform "impossible tasks".

But Commons leader Jack Straw called it a "good thing" that central government was driving changes in Whitehall.

Lord Wilson, interviewed for the BBC Radio 4 series Shape Up, Sir Humphrey, said: "One of the characteristics of New Labour when it came to power was the way it asserted political control over the machinery of government.

"It staged a coup, first of all against the Labour party and then against the processes of government."

The centre has played a part in trying to drive reform and trying to challenge ministers to perform and I think that's a good thing Jack Straw Leader of the Commons

He added: "Politicisation is about political control of the government machine being much more tightly gripped within relatively few hands and I think that is what has happened."

Lord Wilson also said that policy advisers who were not civil servants had "very great influence and weight", and this meant decision-making had become too centralised.

Home Office problems

Lord Butler, Cabinet secretary from 1988 to 1998, said: "The Home Office has had huge problems to wrestle with and the initiatives that have been loaded on it have been more than it has been able to bear.

"So in one sense it is true that the civil servants have let the politicians down, but I think [that is] because the politicians have asked them to do impossible tasks."

He urged politicians and the civil service to re-establish a partnership with more focus on "doing what is right for the nation [and] less attention catching initiatives".

He admitted that civil servants may have been reluctant to say no to ministers who wanted to implement changes immediately.

'Short sighted'

Another Cabinet secretary, Lord Turnbull, spoke of "always swimming against the tide" in trying to get decisions considered by cabinet committee or other bureaucratic methods.

Lord Turnbull, who took over from Lord Wilson in 2002, said there was potentially a downside when No 10 and No 11 Downing St took over policies that could be handled by departments.

"It's often a short-sighted view because if you are constantly taking something over you will not develop the capability and also poeple won't develop the sense of pride, they will actually feel belittled."

However, Mr Straw denied that Labour had damaged the civil service.

He said: "What we have sought to do is to introduce major changes in the civil service, for example by getting outsiders into the civil service, and that's been really helpful.

There is no point in collecting 'yes' men around you Gus O'Donnell Cabinet Secretary

"The centre has played a part in trying to drive reform and trying to challenge ministers to perform and I think that's a good thing."

And current Cabinet Secretary Sir Gus O'Donnell said: "The civil service today is in an incredibly healthy state. We are attracting the best, we're getting in very qualified people, we are making them do ever more demanding jobs.

"People don't realise how much difference... we do make to people's lives everyday. "

He added: "I find it totally straightforward to have told both the chancellor and the PM what I think.

"There is no point in collecting 'yes' men around you. Both PM and chancellor are big enough beasts to not want that. I don't buy this story about politicisation."