The Lords committee which reviews the constitutional implications of new legislation has said the Health Bill poses a risk that “individual ministerial responsibility to parliament will be diluted or that legal accountability to the courts will be fragmented”.

The Lords Constitution Committee today published its first report on the bill. It says it covers “one aspect” - accountability - and the committee may “in due course additionally report on further aspects of the bill”. It is chaired by Labour peer Baroness Jay, a former leader of the Lords.

It adds to significant pressure for the government to amend this part of the bill. Ministers have already said they are willing to do so if there is concern about it. It has been repeatedly highlighted as an area of concern by influencial Liberal Democrat peer Baroness Shirley Williams.

The report says: “We are concerned that the bill, if enacted in its current form, may risk diluting the government’s constitutional responsibilities with regard to the NHS.”

It says bill clauses which require the health secertary to “keep under review the effectiveness” of the NHS Commissioning Board, and publish an annual report on performance of the health service, “will make a modest contribution towards accountability”.

But it says: ” The combination of these changes [in the bill] matters, constitutionally, because it is not clear whether the existing structures of political and legal accountability with regard to the NHS will continue to operate as they have done hitherto if the bill is passed in its current form.

“As such, the house will wish carefully to consider whether these changes pose an undue risk either that individual ministerial responsibility to parliament will be diluted or that legal accountability to the courts will be fragmented.

“Moreover, it is not self-evident that the proposed changes are a necessary component of the government’s reform package. Given the uncertainty as to the interpretation of the provisions proposed in the bill, could not the relevant wording contained in the 2006 [National Health Service] Act be retained?”

Other issues raised by peers ahead of the Lords second reading of the bill, on 11 October, include competition regulation and patient voice proposals, for example concerns about the powers and independence of HealthWatch.

Labour lead health spokeswoman in the Lords Baroness Glenys Thornton told HSJ the party may support a bid for parts of the bill to be considered in a separate bill committee which, along with other moves, could delay its progress.