Jeremy Hunt, the new health secretary, personally intervened to encourage the controversial takeover of NHS hospitals in his constituency by a private company, Virgin Care, raising fresh concerns last night over his appointment.

Hunt, who replaced Andrew Lansley in last week's cabinet reshuffle, was so concerned by a delay to the £650m deal earlier this year that he asked for assurances from NHS Surrey officials that it would be swiftly signed.

Virgin Care, which is part-owned by Sir Richard Branson's Virgin Group, subsequently agreed on a five-year contract in March to run seven hospitals along with dentistry services, sexual health clinics, breast cancer screening and other community services. The takeover took place despite concerns being raised in the local NHS risk register about the impact on patient care following the transfer of management from the NHS to one of the country's largest private healthcare firms, until recently known as Assura Medical.

The director of nursing highlighted the danger of "significant issues" emerging during the first year of Virgin Care control, which NHS Surrey has tried to ameliorate through contractual controls. There was also prolonged wrangling between NHS Surrey and Virgin Care over the terms of the deal, including staff's terms of employment. However, during the lengthy delay before the deal was agreed, Hunt intervened to ask for assurances from the head of the primary care trust "that the delay is to ensure the best possible outcome for patients and staff". Writing on his website about the issue, he added: "I hope that Assura and NHS Surrey are able to complete the transfer of services soon, but I am glad they are crossing every T and dotting every I."

The shadow health secretary, Andy Burnham, said last night that the revelation would add to concerns about Hunt's appointment and his affinity to big business so soon after the furore over the minister's relationship with Rupert Murdoch's News Corp while he was culture secretary during the attempted takeover of BSkyB.

Burnham said: "People will be worried that what happened in Surrey will happen to the rest of the NHS under Mr Hunt's leadership. Yet again Jeremy Hunt bent over backwards for powerful private interests. Never before has a health secretary handed over his local NHS lock, stock and barrel to the private sector.

"If what has happened in his own patch is his blueprint, then now's the time for him to be honest with patients and staff. It is time the health secretary broke his silence on his plans and told the public how far he wants to privatise the rest of the NHS in England."

A spokesman for Hunt said his intervention merely showed that he "cares about the interests of his constituents and has been working in the best interests of his constituents".

However, doubts over Hunt's new role have also been sparked by the revelation that he co-authored a book that supported transforming the NHS into a system of universal insurance where patients buy health care from the provider of their choice.

The book, Direct Democracy: An Agenda for a New Model Party, sets out an alternative vision for a dismantled NHS. It says: "The NHS was designed over half a century ago, at a time of rationing and deep poverty. It was, and remains, a child of its time, conceived on the principle that the beneficent state should be a monopoly provider. But we know today that monopolies rarely act in the best interests of consumers. Because government both funds and provides health care, medical professionals are beset with political targets and central direction, distorting clinical priorities and preventing innovation."

It adds: "We should fund patients, either through the tax system or by way of universal insurance, to purchase health care from the provider of their choice. The poor and unemployed would have their contributions supplemented or paid for by the state."

Hunt also has a record of supporting the use of homeopathy to treat illnesses and it is claimed that he attemped to remove a tribute to the NHS from the Olympics opening ceremony.

A source close to Hunt denied that the minister wrote the section in the book about the NHS and said that "it does not reflect his views".