Lord Warner the health minister responsible for the £12.4bn NHS IT project is to retire at the end of the year.

No 10 has announced that the Labour peer will retire at the end of the year, in what was described as a "personal decision".

The BBC reported that Downing Street had denied that his departure was linked to the growing difficulties over the NHS IT programme, and delays to the implementation of the national electronic record system.

Since the 2005 election Lord Warner – a former special advisor to Jack Straw – has served as deputy to health secretary, Patricia Hewitt, with direct responsibility for some of the most contentious aspects of the government’s health reforms, including the ministerial lead on competition and choice.

Lord Warner, 66, has been closely linked to the CfH programme and repeatedly dismissed any criticism of the project. In October he rejected calls by leading computer science academics for a review of the technical architecture of the project to establish the scale of the risks facing the National Programme for IT (NPfIT).

In June following the publication of the National Audit Office (NAO) report on NPfIT Warner was bullish about the progress of NPfIT, despite the NAO report stating that NHS Care Records Service was two years late and the total cost of the project had doubled to £12.4bn.

At the Department of Health press conference on the NAO report Lord Warner told E-Health Insider that he was absolutely sure both the summary national part of CRS and the detailed local clinical record components of CRS would be fully delivered by 2010. “I have no doubts in my mind whatsoever.”

And in May Lord Warner appeared to muddy the waters over the cost of the programme when he said the price tag for NPfIT, by then officially stated as £12.4bn, would actually end up as £20 billion.

A No10 spokesman told the Daily Mirror that Lord Warner’s retirement was not linked to the NHS digitisation project: "His decision to retire has nothing to do with that at all. He wants to spend more time away from his red boxes."

It is not clear which health minister will take over Lord Warner’s responsibility for the NPfIT, which is currently being reviewed by the DH.