The government confirmed last night that health minister Lord Darzi would be leaving the government and published his resignation letter to the prime minister.

Health Service Journal broke the news that Lord Darzi was quitting as health minister online early yesterday evening. The Department of Health and Number 10 later issued statements they had originally intended to publish today.

In his letter to Gordon Brown (see PDF, right), Lord Darzi thanked the prime minister for having given him “the freedom to make tough but important decisions, and the support to make change happen” but said the time had now come for him to return to care for his patients, lead his academic department and continue his research full time.

Lord Darzi continued practising as a surgeon while he was a minister and was thought to be working around six and a half days a week.

He was appointed to Mr Brown’s “government of all the talents” in 2007 and charged with carrying out the next stage review to set the direction of the health service for the next decade. His report, High Quality Care for All, was published last July. It made quality of services the organising principle for the NHS.

In his resignation letter, Lord Darzi told the prime minister: “I believe that it took great courage to appoint a frontline doctor to undertake a fundamental review of the future direction of the NHS.”

In his reply (see PDF), Mr Brown wrote that Lord Darzi had not just written a report, but “created a movement for change and improvement across the health service”.

He thanked the minister for his “outstanding” contribution to government and “immense” contribution to the NHS.

“Your leadership has made possible far greater clinical involvement in decision-making at every level,” he added.

King’s Fund chief executive Niall Dickson said Lord Darzi had made a huge contribution in his relatively short period of time in government.

“His legacy will be to have put the quality of care patients receive centre stage – and to have reinforced the need to involve doctors, nurses and other professionals in the reform process.”

However, he added: “It is too early to say whether Lord Darzi will have made the difference he wanted and there is still much to do to turn his vision into reality throughout the health service.”

Downing Street announced last night that Lord Darzi will take on a new role as a health and life sciences ambassador for the government and will chair a new NHS global forum to promote the NHS and the UK’s life sciences industry around the world.

“Lord Darzi’s new focus will be on supporting the government’s life sciences strategy and the contribution which the NHS can make to supporting a strong, vibrant health industry in the UK and around the world. In this capacity Ara will chair a new forum called NHS Global, the purpose of which will be to support the promotion of the NHS and UK healthcare and life-sciences industry internationally. The forum, which will be established in the coming weeks, will be made up of representatives from government, the NHS and representatives from across the life-science industries,” a statement said.

He will also advise on health reforms in the NHS and global public health.

Lord Darzi will stand down when Parliament goes into recess for the summer.

Health secretary Andy Burnham said: “The next stage review has set a defining vision for the national health service for years to come, embedding quality at the heart of everything it does, and engaging thousands of staff and patients along the way. This vision is now being delivered locally, by frontline staff, who will continue to develop and deliver the changes set out in the next stage review in the years ahead.”

Last month Lord Darzi told HSJ there was “absolutely” no substance to rumours he has been unhappy with the political aspect of his role.

Asked what he would be doing this time next year, he made it clear he expected not to be a minister: “The people who will make change in the NHS are not here [in the Department of Health], they are out there. And I will be with them doing my work.”