The government faces almost 250 amendments to its Health and Social Care Bill in the Lords and is under pressure to make concessions on four key policy areas or risk losing the legislation altogether.
The bill enters its committee stage in the Lords today, which is expected to continue over at least three sessions in the coming week.
But the Lords, where the government does not have a majority, could further prolong the debate and prevent the bill reaching its report stage before Parliament is dissolved for a general election.
Liberal Democrat health spokesman Lord Clement-Jones told HSJ: 'There are four key areas where the government is going to have to give way if they want to get the bill through. '
The areas are: the fate of community health councils; governanace of care trusts; the definition of nursing care for elderly people; and the controversial clause 67, which critics say could allow the health secretary to publish identifiable health information without patient consent, and to suppress use of statistical information.
An informed source in the Lords said: 'This will be a very long drawn-out committee stage.
The question is whether we get any report stage.
'The whole issue is whether the government is prepared to compromise or to risk the whole bill or clauses of it. '
There was 'a fairly strong mood' among peers of all parties to fight for concessions from the government, he added.
'The bill has some quite useful things, but nothing I would die in a ditch for. I want the government to give on things like nursing care. '
The government is already giving ground over clause 67.
A letter from the Department of Health to the Lords select committee on delegated powers and deregulation says ministers are 'minded to introduce a government amendment' to restrict the health secretary's powers over statistical information.
Powers would be limited to acting in cases where NHS patient information was used 'for marketing and other promotional activity which the secretary of state considers to be contrary to the interests of the NHS'.
London Health Link chair Elizabeth Manero said a meeting with an all-party group of peers had shown 'very solid support' from all parties for further amendments on the future of CHCs and patient representation.
Association of CHCs for England and Wales former chief executive Lord Harris said he had tabled an amendment calling for a national patients' body which 'should have responsibility for staffing and resourcing local patients' councils'.
Late in the day: DoH briefing riles CHCs
CHCs expressed their anger this week that the Department of Health had issued a detailed briefing on the future shape of patient representation in the NHS just days before the Lords debate.
The document was sent to CHCs on Friday, allowing scant time to take on the new information before the final deadline for the Lords to submit amendments to the bill.
London Health Link chair Elizabeth Manero claimed that if independent advocacy services were commissioned by local authorities, as suggested in the new document, a conflict of interest could still arise over representing users of joint health and local authority services.