The government's health plans for the NHS in England require such substantial changes that the entire bill may have to be dropped, according to the British Medical Association.

The doctors' union called for a series of changes in its submission to the government's six-week listening exercise, which was called in response to mounting criticism of the Health and Social Care Bill. In particular, doctors demand that the regulator's new duty to promote competition be dropped. They also want to see timetables relaxed and the net of responsibilities that the bill places on GP consortiums spread to involve other clinical staff.

The Deputy Prime Minister, Nick Clegg, is due to deliver a speech on health reform that will be closely watched, given his tough rhetoric on NHS reform in recent weeks.

Although he will call for substantial changes, he is expected to echo David Cameron's speech last week on the need for reform. The Liberal Democrats share their main concern about the bill with the BMA: that competition clause. The BMA wants a greater emphasis on collaboration; the Liberal Democrats endorsed this at their spring conference. To this end, Clegg will say:

People want choice – over their GP, where to give birth, which hospital to use. But providing that choice isn't the same as allowing private companies to cherry-pick NHS services.

As the listening exercise – essentially a second consultation period – draws to a close, it seems a consensus is no closer.

The government has repeatedly promised substantial change and rethinking of the bill (while reiterating the need for reform), but the question is how far it is willing to go with watering down the competition clause. Given that a free-market philosophy permeates Andrew Lansley's entire bill, and it has the support of many Conservatives, this will prove problematic.

Among the groups that have backed the government's plans for greater competition are Reform, a pro-market think tank, and the NHS Confederation, which represents managers. Doctors on one side and managers on the other: whose advice would you rather take?