The government's controversial health reforms are a "mess" and unnecessary, according to the former NHS chief executive who helped drive through reforms under Tony Blair.

As the health secretary Andrew Lansley prepares to make a series of concessions to Liberal Democrat peers this week, Lord Crisp launched one of the strongest attacks on the health and social care bill by a former NHS grandee.

Crisp, a crossbench peer who was chief executive of the NHS between 2000 and 2006, told Radio 4's The World This Weekend: "I think it's a mess, is my straightforward view of it. I think it's unnecessary in many ways and I think it misses the point. I think it's confused and confusing, and I think it's unfortunately setting the NHS back."

The remarks by Crisp, who also served as permanent secretary at the Department of Health, will come as a blow to Lansley who claims that his plans to devolve commissioning powers to GPs are a continuation of the Blair reforms. Most of these were introduced in the latter period of the Blair premiership when Crisp ran the NHS.

As the health and social care bill reaches its final stages in the House of Lords, Lord Clement-Jones, the Lib Dem peer, is tabling a series of amendments in the contentious area of competition in the NHS with the blessing of Nick Clegg. This has prompted concerns among some senior Tories that the deputy prime minister is planning to abandon a deal with David Cameron to ensure the bill is passed.

Senior Lib Dem sources say they do not expect to "emasculate" the contentious third section of the bill which deals with competition in the NHS. But they do expect Lansley to give some ground.

It is understood that Lansley is currently not minded to accept any Lib Dem amendments or to sanction any fresh government amendments. He feels that two of the Lib Dem's concerns have already been dealt with. These are the call for foundation trusts to co-operate rather than compete and for trusts to be placed under a duty to achieve greater equality of outcomes.

A third Lib Dem demand – that EU competition law should not apply to the NHS – is more problematic. DoH lawyers have advised that the NHS has been covered by this since the Blair reforms. Lansley does not see this as a political problem. But he believes that the legal advice makes it difficult to move on this area.

Lansley is prepared to give ground in two areas. These are that:

• Monitor, the NHS trusts regulator which is charged with improving efficiency, would retain its role in overseeing oversight of free-standing trusts beyond 2014.

• The Competition Commission would not have the main role in reviewing the devlopment of competition. This would rest with Monitor.

Simon Hughes, the Lib Dem deputy leader, told the Sunday Politics Show on BBC1: "Watch this space. You will see a bill that will protect and defend the NHS which was a Liberal idea in the first place."