Health secretary Frank Dobson tackled critics of the private finance initiative head-on this week, as sceptical MPs quizzed Department of Health officials on the scheme.

A week after the widely publicised spat between prime minister Tony Blair and the British Medical Association, Mr Dobson said the opponents of PFI 'rule it out on principle, regardless of the facts'.

'We take a pragmatic view - what counts is what works, ' he told a conference in Solihull.

'Some people say that because the government borrows more cheaply than the private sector, PFI will automatically be more expensive.

'This ignores altogether the offsetting savings that can come from better design, no cost over-runs and more efficient maintenance.'

Mr Dobson also told the conference on lifelong learning that hospitals had always been built 'by the same profit making private construction companies who are now involved in PFI'.

The difference was that 'in the old days these companies could augment their profits by cost over-runs, delays and cutting corners' while under PFI 'they can only make their profits by sticking to cost, delivering on time and properly maintaining the buildings'.

This argument was repeated at a hearing of the Commons health select committee, which is conducting a short investigation into PFI as part of its annual overview of NHS funding.

But Labour veteran Audrey Wise asked Norfolk and Norwich Health Care trust chief executive Malcolm Stamp why the NHS could not stop such problems, without resorting to PFI.

Mr Stamp, back at the committee after being accused of with-holding information from it earlier this year, said: 'I do not disagree with Mrs Wise.'

But he added: 'It would appear that in 48 years we were not able to do this in the NHS. There is no reason that we cannot, but it has not happened in my lifetime.'

Committee members took up the point with NHS finance director Colin Reeves, who said three types of risk - building and cost over-runs, poor design and service availability - were transferred to the private sector in PFI schemes.

Liberal Democrat GP Dr Peter Brand argued that if the NHS 'got better' at building schemes with public money, the amount of risk transferred would fall and proponents 'will be looking for new ways to justify PFI'.