Andrew Lansley has refused to abandon the “principles” of his NHS reforms as he fights mounting political pressure over the radical shake-up proposed in the Health Bill.

The health secretary insisted the reforms would “strengthen” the health service, as one Liberal Democrat MP called for the entire package to be dropped and Labour attacked it as a “full blown” privatisation.

The government has already announced a “pause” to the legislation while it looks for ways to accommodate growing disquiet over the scale of the planned changes within the NHS.

Nick Clegg has put the bill at the centre of his efforts to demonstrate Liberal Democrat influence in the coalition after his party’s thumping at the polls last Thursday (5 May).

One of his backbench MPs, Andrew George, publicly called for the bill to be abandoned altogether, issuing a statement in which he said it undermined the “ethos” of the NHS.

Saving the NHS was “more important than saving a few egos in the coalition”, he said.

He was one of dozens who challenged Mr Lansley during an ill-tempered Labour-led debate in the Commons, which the opposition hoped would further expose intra-coalition tensions.

Mr Lansley told Mr Mr George the Coalition Agreement “supports essentially all of the principles of the bill” apart from scrapping some NHS bodies - which had been agreed by Lib Dem ministers.

And he said he was more interested in improving services for patients than in political argument.

“There will be substantive changes to the bill in order to deliver improvements for patients. But there is only one issue for me: will it deliver better care for patients?” he said.

“That is why we are going to pursue NHS modernisation, it is why we will stick to our principles and it is, equally, why we are listening in order to improve the bill.”

Shadow health secretary John Healey said “setting up the NHS as a full-blown market… is the wrong prescription for our NHS and it’s patients that will suffer in future”.

Labour leader Ed Miliband said there was no popular support for the planned changes and he urged ministers to abandon the legislation altogether.

“This is a bad bill - it is a free market, free-for-all for the NHS. The government should dump the bill and start again. People don’t want this for our NHS,” he said ahead of the debate.

But Mr Lansley said he was completing “half-baked” reforms started under Labour and accused the opposition of abandoning support for the changes under pressure from trade unions.

Downing Street said the listening exercise on the NHS would continue into next month.

The government escaped a damaging rebellion in a Labour-called vote against the health shake-up but saw its majority cut to 53, with several Liberal Democrat MPs deliberately staying away.