Former Cabinet minister Andrew Lansley has said he will step down from Parliament at the next general election, when he will attempt to find an “international” role.
The announcement comes after Mr Lansley was replaced as Leader of the House of Commons by William Hague, who made a shock-resignation as Foreign Secretary on Monday.
In a letter to David Cameron, the South Cambridgeshire MP said he told the Prime Minister earlier this year that he would not stand for re-election in 2015.
“You supported my ambition to continue my life of public service in challenging and important roles,” he wrote.
“I am grateful to you now for expressing your support for me to take such a role in international public service in the months ahead.”
The document does not explain which post Mr Lansley is referring to.
There had been widespread speculation that he could be nominated as the UK's next European commissioner, but Mr Cameron confirmed on Tuesday that the former Leader of the Lords, Lord Hill, had been put forward.
If approved by the European Parliament, Lord Hill will serve a five-year term until 2019.
In his response to Mr Lansley, the premier wrote: “You have much more to give in terms of public service, and I look forward to being able to support you in doing so in the months and years ahead.”
Downing Street declined to comment on whether Mr Lansley was being lined up for an international role.
Mr Lansley’s impending departure from Westminster comes amid a wide-ranging cabinet reshuffle, which saw veteran Tory minister Ken Clarke step down as Minister without Portfolio, and former controversial Education Secretary Michael Gove replaced by Nicky Morgan.
Additional reporting by PA