Liberal Democrat peers are under pressure to make more changes to the Health Bill after a manoeuvre by the party’s leadership in support of the bill backfired at its spring conference on Sunday.

The conference voted by 314 to 270 to remove a motion clause that called on the party’s peers to support the bill at its third reading.

The support urged in the motion would have been subject to peers securing amendments to remove review by the Competition Commission, retain Monitor as regulator of foundation trusts and ensure that trusts have to justify “any substantial increase in their private income”.

The vote could see party figures unhappy with aspects of the bill now press peers to table fresh amendments, for example, on restricting outsourcing and securing a majority of councillors on health and wellbeing boards.

Baroness Williams, a figure popular with the party’s rank and file, proposed a motion entitled “Protecting the NHS: the Shirley Williams Motion”. Motions would not normally carry the proposer’s name in their title.

One peer admitted afterwards that using Baroness Williams’ popularity in such a blatant way may have provoked delegates who felt patronised by the manoeuvre.

Several peers closely involved with the bill accused their MP colleagues of allowing it to progress too far unchallenged.

One told HSJ: “I am appalled at the heavy lifting we have been left to do as a result of a lack of scrutiny by the team in the Commons.

“In an impossible situation we have done the best we can to improve the bill, but no one would have started from here.”

Another peer said: “This could mean we are under pressure from the party to secure further amendments to the bill.”

Anger among peers has been stoked by a perception that deputy prime minister Nick Clegg and senior colleagues paid too little attention to the bill at its outset.

Asked during a question and answer session why he allowed it to progress at all, Mr Clegg said: “We face the dilemma that the population is getting older and people live for longer, and that’s great, but the basic idea of the bill is to create a system for the [GPs], who know the patient best, to keep them well in the community and not be shunted off to hospital.

“If I felt this bill was privatising the NHS the bill would not have seen the light of day.”

Baroness Williams told the conference debate that if the Health Bill was not passed “we are left with the 2006 act, which brought in privatisation, and we’ve stopped that in this bill”.

But former MP Evan Harris, himself a doctor, said the amended bill “still has no block on wholesale outsourcing of commissioning work, which should be a public function, and no requirement to avoid destruction of services because of outsourcing.

“If orthopaedics goes, for example, the acute service would not be viable.”

Martin Tod, who led the campaign against the bill inside the party, said: “It is additional complexity when the NHS already faces the extremely difficult Nicholson challenge [to save £20bn by 2015].

“It is also centralisation, the [NHS] Commissioning Board will take 40 per cent of the budget and become the biggest quango ever seen.”