Nick Clegg sought to soothe anxious Liberal Democrats after they dealt him a sharp rebuke over the coalition’s controversial NHS reforms.

The deputy prime minister emphasised his party’s distinct identity, claiming to be neither of the left nor right but governing “from the middle for the middle”.

Activists at the Lib Dem spring conference in Sheffield overwhelmingly passed a motion condemning proposals for putting GPs in charge of commissioning services.

Speaker after speaker demanded a rethink, with party doyenne Baroness Shirley Williams branding the changes “lousy” and backbencher Andrew George insisting the Lib Dems should not be “the architects of [the NHS’s] demise”.

John Pugh MP said the reforms would create the “biggest quango in the country”, and only health secretary Andrew Lansley thought they were a good idea.

Mr Clegg played down the heavy defeat during a question and answer session with members later, insisting “almost all” the amended motion went “with the grain” of the government’s reforms.

“I am now going to look at it in considerable detail,” he said. “Because I think a lot of what we have talked about this weekend - greater accountability, greater transparency, making sure we don’t have a wilful disruptive approach to diversity of providers and don’t allow the profit motive and price competition to run a coach and horses through the NHS - that’s precisely what is happening.”

However, the vote will increase the pressure on the leadership to try to water down the proposals and reduce the scope for private sector involvement in health provision.