The NHS is ‘not fit for the future’ and unless it undergoes radical change it may be forced to abandon free healthcare for all, in the future, the service's top doctor has warned.

Medical director of NHS England Professor Sir Bruce Keogh said the NHS must become far less reliant on hospitals and needed a ‘complete transformation’ of the way it operates.

Sir Bruce told the Guardian: ‘If the NHS continues to function as it does now, it’s going to really struggle to cope because the model of delivery and service that we have at the moment is not fit for the future.’

GP surgeries need to be given more resources to cope with the pressures of demand and tight budgets, he added.

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Professor Sir Bruce Keogh, medical director of NHS England, warned the health service needs a complete 'transformation' if it is to continue providing free healthcare for all in the future. He said it needs to move away from a reliance on hospitals and that GPs must be given extra resources to cope with demand

In order for the NHS to keep itself sustainable, he said more services need to happen under the same roof – for example diagnostics tests and an expanded range of treatments at their GP surgery.

Sir Bruce added: ‘If not, we will get to a place where the NHS becomes unaffordable and we will have to make some very difficult decisions which will get to the very heart of the principle of the NHS and its values.

‘This will open up a whole series of discussions about whether the NHS is fit for purpose, whether it’s affordable, and whether the compact with the citizen of free healthcare for all is sustainable in the longer term.’

He added: ‘Too many patients find the NHS fragmented (and) confusing. They find that they get pushed from pillar to post; they feel like a ball in a pinball machine at times.’

He denied claims that ambulance services, A&E and GP surgeries are struggling to cope and are in crisis – despite waiting times at A&E being at their worst levels in a decade.

Three of the 10 ambulance trusts in England have had to declare a critical alert over the winter.

But Sir Bruce denied it was a crisis.

He said: ‘Everybody that’s working out there in the NHS knows that they’re under a lot of pressure at the moment.

'They don’t like the term "crisis" being applied willy-nilly.

Britain's top doctor said despite the intense pressures on A&E departments and ambulance services across the UK, the NHS is not in crisis. He said: 'The word "crisis" implies that you can't deal with it'

‘It’s an evocative term which is also provocative and is used too freely for the wrong reasons.

'It’s a period of unprecedented pressure, of undue pressure. But the NHS is facing very difficult times, yes. The word "crisis" implies that you can’t deal with it.’

He added that the frontline services ‘are going through a critical phase’ but would recover.

A Department of Health spokesman said: ‘In common with healthcare systems around the world, the NHS is facing unprecedented demand, but undermining the principle of services being free at the point of use is not the answer.