The MP for South East Cambridgeshire, Sir Jim Paice, will stand down at the next election.
The former Farming and Food Minister said, “I have been fortunate to represent a wonderful constituency for what will be almost 28 years by the next election.
"It has always been at the forefront of economic growth in the UK whilst retaining much of what is great about our country.
"I have also been privileged to serve in two Governments including as the Minister of Agriculture which had long been my ambition.
"It has been an incredibly exciting and rewarding life, but if I go on I am committing myself into my 70s which I do not believe would be right.
"I think now that it is time for the Conservative Party in South East Cambridgeshire to look to someone else to carry their hopes and aspirations over the coming years.”