The former Liberal Democrat MP for Colchester, Sir Bob Russell, is to stand as a candidate in the general election, despite retiring from politics after his defeat in 2015.
He lost his seat to Conservative Will Quince who was returned with a 5,575 majority.
As a Liberal Democrat MP, Sir Bob served his constituency for 18 years, after first being elected in 1997.
In a statement the 71-year-old said he was "under a lot of pressure to stand".
"I have given the matter considerable thought," Sir Bob said.
"My wife has said she will back me, and pledges of support and encouragement have come from friends and party members."
Speaking to the BBC, Sir Bob denied he was too old for the job, adding he was younger than the region's longest serving MP, Saffron Walden's Sir Alan Haselhurst.
Sir Bob said: "It's an attitude of mind. I am pretty fit. We are living longer. We have an ageing population and I think an ageing population needs to have representation."
Mr Quince said he would not be focusing on his opponent but pointed out that "people had voted for change" in 2015.
Since leaving office Sir Bob, who grew up in the garrison town, has been offering tours of his former constituency for £5 a time, with the money going towards funds for a statue of a local author.