Prime minister Tony Blair has warned against creating an independent NHS. He said it would slow down decision-making and be in danger of becoming distracted by special interest groups.

Speaking at a King's Fund debate on Monday, in what will almost certainly be his final speech on health as prime minister, he argued that the major elements of the last 10 years of reform would outlast future governments, while also conceding mistakes over the creation of primary care trusts.

Mr Blair said he was wary of calls to create an independent NHS board, saying: 'If it is a way of making decisions, I can understand the point of it. My worry is if it became a means of avoiding decisions.

'Someone has got to take the decision if it is a driving force for change, rather than a brake on it,' he said. 'You can talk about taking the politics out of the NHS but these are political decisions.'

Mr Blair returned repeatedly to the point that an NHS based on choice, plurality and competition would not be dismantled by his successors. 'I think that a less monolithic NHS with more competition, with practice-based commissioning and payment by results, will stay in place. I can't see the basic framework being changed. I can't see any government turning their back on that.'

He also indicated that social care could benefit from the same dose of competition and choice as healthcare has done.

The prime minister commended the NHS's progress on eliminating waiting lists through the use of competition and improvements in emergency care, as well as the treatment of heart disease and cancer.

'In the first two years we didn't push forward fast enough [on introducing reforms],' he admitted. However, he defended the decision to increase NHS funding in advance of those reforms bedding in: 'I have always thought that dealing with reform before under-investment was addressed would be difficult.'

After criticism of reorganisations by speakers including RCN general secretary Peter Carter, Mr Blair conceded that 'fair points can be made about reorganisation'.

'There was a lot of support for primary care groups at the time and in terms of where we were it made sense to move to a system [of 303 primary care trusts]. It seemed like a good thing to do. In retrospect it would have better to avoid it but at the time it was difficult to foresee.'

He defended charges that reforms had lost the faith of NHS staff, arguing that like Margaret Thatcher's reorganisation of industry in the 1980s, while the changes are still taking place it is extremely difficult to win internal support. 'People make a more rational assessment at the end. We have to hold our nerve while dealing with those points that are reasonable.'

The prime minister also paid tribute to health secretary Patricia Hewitt's championing of the ban on smoking in public places, which British Medical Association chair James Johnson called the Blair government's single biggest achievement. Mr Blair said: 'There were some of us who wondered about the public reaction, but it was the right thing to do.'