Pressure from GPs may yet force the government to scrap its NHS reforms, according to the activist GP behind an anti-Health Bill motion to be debated at the Liberal Democrat spring conference this month.

Dr Charles West, GP and chairman of Shrewsbury Liberal Democrats, told GP: 'We are now saying that the Lansley Bill is not amendable, it cannot be made safe and therefore it must be dropped.'

Dr West is among a group of party activists who drew up the motion. If it is debated and passed by a majority at the Liberal Democrat conference it will become party policy. 'It doesn't necessarily mean the Bill will not pass but it gives a strong message,' Dr West said.

His comments came as GPC chairman Dr Laurence Buckman wrote to the profession this week restating the GPC's rejection of the Health Bill.

'We urge the government to listen and act on the concerns of GPs in the interests of the future of the NHS and what is best for patients - there is a sensible alternative to proceeding with this Bill,' he wrote.

The Bill came under further pressure this week as Liberal Democrat leader and deputy prime minister Nick Clegg wrote to MPs and peers in the party who support further changes to the Bill.

In the letter, co-signed by Baroness Shirley Williams, Mr Clegg said he wanted reassurance that the NHS would not be privatised 'like the gas, electricity or water industry'.

The letter endorsed Liberal Democrat peers' calls for a reduction in the Competition Commission's powers, protection of the NHS from EU competition law, a call for GP commissioners to declare their financial interests and limits on foundation trusts.

Dr West described Mr Clegg's letter as a 'sticking plaster exercise'. He said that it was now up to the medical profession to put pressure on the government. 'If the GP voice is loud and getting louder that will do a lot to persuade David Cameron to drop the Bill.'

Meanwhile, clinical commissioning group leaders in two areas of east London wrote to the prime minister this week to call for the Bill to be scrapped.