Patricia Hewitt resigned as health secretary yesterday after Gordon Brown's appointment as prime minister.
In her resignation letter to Brown, Hewitt cited personal reasons for her decision, though she had been widely expected to be moved in Brown's first reshuffle, which is due to take place today.
In his reply to her resignation, Brown paid tribute to her work in bringing in the smoking ban in England, which will come into force on 1 July, reducing health waiting times and driving forward the government's market-based reforms to the NHS.
There was no mention of her contribution to adult social care since her appointment in May 2005, a time which has seen social care assume a higher profile in the Department of Health, particularly with the appointment of David Behan as director general of social care last June.
However, it has also seen councils' financial problems worsen and evidence of cost-shunting from primary care trusts to local authorities.
Her successor is expected to be named later today.