Dr Cook, who has quit her job as a hospital consultant after 26 years, said the extra cash being ploughed into the health service was failing to make a difference at the "sharp end".
She accused ministers of using the NHS as a "plaything" and a "political football".
Labour has pledged record levels of NHS investment in exchange for reform.
But ministers have come under fire for plans to bring in more private management - and for not doing enough to solve a growing recruitment crisis.
'Weight of responsibility'
According to the Daily Telegraph newspaper, Dr Cook, a consultant haematologist at St John's Hospital in Livingston, near Edinburgh, attacked Tony Blair for "not giving a damn about patients".
But she told BBC Radio 4's Today programme she did not directly blame the government for her decision to take early retirement.
"I'm leaving because the stresses have got to me and I feel that my time has come," she said.
"I can't really any longer cope with the enormous weight of responsibility that is expected of a consultant.
"I have carried it for 26 years. The pressures increase enormously."
'Decreasing staff'
She went on: "You often feel that if they would just leave you to get on with the job you would do very well."
She said the pressures of the job were "other than clinical pressures".
"I think that increasing measures to improve safety, and governance and accountability, all these are very good measures.
"But to expect to be able to do that with the same body of staff and often with a decreasing staff is totally unreasonable.
"Somehow at the sharp end the money never seems to materialise."
Dr Cook said the NHS should be taken out of direct government control.
Marriage break-up
"What I'm trying to criticise is the system. The system is all wrong.
"I was trying to put over the fact that I think the NHS should not be a political football. It should not be something that is the plaything of the government.
"It should be under an independent body which obviously has powers to direct what should happen."
Asked whether she was motivated by bitterness over the break-up of her marriage, Dr Cook said: "This is absolute nonsense.
"I'm not really specifically trying to get at the government, certainly not at this government.
"I'm just saying that there are better ways of running the NHS and we have not addressed them."