Labour are privately playing down their battle against NHS reforms as the Health and Social Care Bill returns to the Lords, with some in the party believing they should give the government enough rope to hang themselves, party sources have told the Huffington Post UK.

Although the party line hasn't changed and shadow ministers are still calling on the government to drop the Bill, senior party workers behind the scenes are assessing whether the reforms will cause the coalition to lose the next election.

The party have warned Wednesday "won't be a big day", and sources in the Lords have indicated they are more concerned about the "toxic" sections in the bill focusing on competition and surrounding NHS regulator monitor, which will be debated at the end of the month.

Privately some Labour strategists are assessing whether the party will ultimately gain if the reforms go through and the NHS is plunged into chaos because of the shake-up. A party source close to the front bench told HuffPost there was an ethical dilemma between principles and politics.

Another source said the resignation or reshuffling of Andrew Lansley would be bad for Labour, because he was rapidly becoming a totemic hate figure in the health service.

These rumblings behind the scenes in the party run contrary to the official line from shadow health secretary Andy Burnham, who highlighted the problem of the competition in the NHS on Wednesday, and warned the reforms risked creating a health service that was "demoralised, destabilised and fearful of the future."

He told BBC Radio 4's Today programme he thought the bill could be defeated. "This bill will damage the national health service.. We should drop the bill."

As Labour back away from the attack, health secretary Andrew Lansley is under renewed pressure. On Tuesday after a Number 10 source was quoted in the Times saying the prime minister wanted to see Lansley "taken out and shot" a Downing Street spokeswoman insisted the health secretary continued to enjoy David Cameron's "full support", despite mounting criticisms of his planned NHS reforms and press speculation about his future in the Cabinet.

According to reports on Wednesday morning the prime minister will throw his support behind the bill.

On Sunday Ed Miliband called for a cross-party alliance against the bill, saying there were just "three months to save the NHS".

Last week the government tabled amendments to the NHS reforms, in an attempt to shore up support before the plans go back to the Lords next week. The changes mean that the secretary of state will be accountable for the health service "beyond doubt" and will, alongside the NHS commissioning board and clinical comissioning groups, have to report on progress in tackling health inequalities.

But despite the changes, the majority of health professionals oppose the bill. On Wednesday morning representatives from the Royal College of Nursing, BMA, Royal College of Midwives and Chartered Society of Physiotherapy wrote to the Guardian calling for the bill to be dropped.