Lansley's spin doctor silenced after briefing against Clegg

In April Jenny Jackson described Lib Dem junior ministers as 'yapping dogs' in an anonymous briefing

The personal spin doctor and attack dog for the embattled Health Secretary, Andrew Lansley, has been muzzled, after senior Liberal Democrats objected to her alleged rubbishing of Deputy Prime Minister, Nick Clegg, and other Liberal Democrat ministers.

The silencing of Jenny Jackson, who was barred from briefing journalists after being caught sending emails that undermined Mr Clegg, is another setback for Mr Lansley in his uphill struggle to win public support for plans to overhaul the NHS.

The row is more evidence of tension within the Coalition over the radical plans put forward by Mr Lansley, which include scrapping primary care trusts and handing over to GP consortiums the responsibility for managing budgets and commissioning healthcare and opening up NHS trusts to competition.

His plans, which were not part of the Tory manifesto nor the Coalition Agreement signed by David Cameron and Mr Clegg, have become the main point of tension in the Coalition.

Earlier this month, Mr Clegg told the BBC's Andrew Marr Show that the reforms were being pushed through too fast, that the 2013 deadline should be put back and that GPs should not be forced to sign up to the new commissioning consortiums. Senior journalists then received emails from Jenny Jackson, quoting things that Mr Clegg had said about the NHS reforms before his party suffered setbacks in the May local elections and the referendum. The clear implication was that the Deputy PM had changed his tune after his party's drubbing at the polls. The email outraged senior Liberal Democrats.

Ms Jackson was already in their sights after an anonymous briefing in April in which a "Tory insider" belittled the contribution of Liberal Democrat junior ministers in Government departments headed by Conservative cabinet ministers. The "insider" likened Liberal Democrat junior ministers to "yapping dogs" who could be largely ignored. Later Ms Jackson was named as the source of these comments.

After speculation that she could be offered as a sacrifice to improve Coalition relations, it was reported yesterday that she had been sacked. That was denied categorically by the Department of Health, though the press office would not comment on whether she was still entitled to brief journalists.

It is the most serious row involving a Conservative spin doctor since the Cabinet Secretary, Sir Gus O'Donnell, complained to David Cameron about a personal attack on the head of the Electoral Commission, Jenny Watson, attributed to a spin doctor working for Communities Secretary, Eric Pickles.

The muzzling of Mr Lansley's spin doctor coincides with the end of the "listening exercise" that signalled the Government's intention to backtrack on the Health Secretary's NHS revolution.

In April, the Government put Mr Lansley's reforms on hold and set up the NHS Future Forum, a group of medical staff, patients' representatives and others, chaired by Professor Steve Field, to take soundings on the proposals.

Making his first comments since the listening exercise finished yesterday, Mr Lansley said he would never privatise the NHS, but appeared ready to bow to some watering-down of the bill.

He told the Daily Telegraph: "We have always been clear that we are ready to accept any changes – substantial and significant – if they help us improve care for patients."

Professor Field will now report on the findings and a revised Health and Social Care Bill will be published towards the end of the month.

In his report, Professor Field is expected to warn against going ahead with Mr Lansley's original plan to compel hospitals to compete for patients and income.

When David Cameron was challenged by Ed Miliband in the Commons last month over whether the "listening exercise" was genuine, the PM promised it will lead to "significant and substantial changes" in the proposed legislation. But there have also been signs of a Tory backlash as Liberal Democrats push for the reforms to be moderated. Writing for the ConservativeHome website, Tory MP Nick de Bois warned that "we are in danger of compromising too much". He added: "The first thing we should stick with is our core principles on reform, but we also have to stick with, and show our support for, our Health Secretary."

The spin doctor in the headlines

It must have been an uncomfortable moment for Jenny Jackson when her boss, Andrew Lansley, stood before the annual conference of the Royal College of Nursing in April and said, contritely: "I am sorry if what it is I am setting out to do has not communicated itself."

Her job, for the past five years, has been precisely to advise Mr Lansley on effective communication. She did this for four years while the Conservatives were in opposition without attracting negative publicity.

Her reward when her boss became a Cabinet minister was to be appointed a special adviser, with a salary of around £55,000 paid by the taxpayer.

It was the intense political pressure that her boss has been under in the past few months that drew this 32-year-old Edinburgh University graduate, nicknamed the "Elf Secretary", into the simmering conflict between Lib Dems and Conservatives who are finding the coalition an increasing strain.

Before her appointment as Mr Lansley's chief of staff in 2006, her professional experience was all in the media and political consultancy. This included working for Newsweek in Pakistan at the time of the 11 September terrorist attacks. She was also treasurer of the Conservatives' Human Rights Commission.