Andrew Lansley has been sacked as health secretary and replaced by Jeremy Hunt, sparking concern about delays to critical NHS service change plans.

The shock announcement was made as part of the ministerial reshuffle on Tuesday.

The government also replaced the Liberal Democrat minister Paul Burstow, who had responsibility for social care reform, with Norman Lamb. Mr Lamb has a strong interest in that subject and was his party’s health spokesman before the 2010 election. 

Junior Conservative ministers Simon Burns and Anne Milton also exited the department, being replaced by Daniel Poulter and Anna Soubry. Only Lord Howe stayed in post. 

Observers said the prime minister believed Mr Hunt – previously the culture secretary – would be better placed to present NHS policy to the public in the run -up to the 2015 general election. 

“He [Hunt] is highly regarded in Number 10 and thought to be able to sell the reforms, and most importantly will play well in the media in the run-up to the election,” said one well placed observer.

Another senior political consultant working with the health service said Mr Hunt would be sensitive to media and public opinion. But he said that may mean he struggles with the concept – enshrined in the Health Act reforms – of “a secretary of state who doesn’t have his hands on the operational levers”.

Mr Hunt came under huge pressure in the spring over his office’s handling of News Corp’s bid to take over BSkyB. The source warned the Opposition and non-Murdoch media would be even more determined to dig up evidence of wrongdoing following his promotion.

In addition, Mr Hunt has very little experience of health, although he was shadow minister for disabled people for 18 months from 2005.

Mr Hunt’s most prominent previous involvement in the health service has been leading a high-profile campaign to stop the closure of services at Royal Surrey County Hospital five years ago.

That stands in contrast to Mr Lansley, who was shadow health secretary for seven years before forming part of the coalition government in 2010. Mr Hunt does not have Mr Lansley’s in-depth knowledge of the service or strong beliefs about how it should operate.

The most widespread fear among senior NHS commentators is that he will not support necessary but controversial moves to cut costs, such as closing hospital services and reducing spending on staff.

One top-level regional manager told HSJ the greatest danger to the NHS was that Mr Hunt, along with Number 10, will resist contentious efficiency and reconfiguration schemes, as the next general election approaches. In recent months Mr Lansley has indicated support for such schemes, and overseen the application of the failure regime to South London Healthcare Trust.

The source said: “It has been possible to get [Lansley] on board with [these] things. My anxiety is that Number 10 will close all that down suddenly, that a lot of things will now be off the table.”

NHS Confederation chief executive Mike Farrar said Mr Hunt’s top priority should be “making sure the NHS is financially sustainable for the future”. 

He said: “The NHS reforms are important, but we must keep our eye on the long-term issues the NHS is facing – an ageing population and growing rates of obesity. Driving change in these areas will be the big test of the success of this government.“

And King’s Fund chief executive Chris Ham said: “The new secretary of state must show political leadership by supporting the case for radical transformation in the delivery of care.

“Although funding pressures on the NHS and social care are an immediate and pressing concern, he must focus on addressing the longer term challenges and ensure change benefits patients.”

More positively, the chief executive of a major charity said Mr Hunt had a “chance for a big charm offensive” with NHS staff as well as the public. The source said that had the potential to help the NHS cut costs, with staff on side rather than resentful, as many are to Mr Lansley.

Meanwhile, the appointment of Mr Lamb has been read by some as an indication the government will step up attempts to reform the funding of long-term care, a difficult subject and one of his long-term interests.