He has told colleagues he will stand down at next year’s council elections.
After 43 years as a councillor, he says he wants to retire and hand on the baton.
He said: “The Labour Party have asked those who are presently councillors whether it would be their intention to put their names forward for consideration as candidates for next year’s elections.
“For my part, I have indicated that it would not be my intention to put my name forward.”
Cllr Milligan said he would be 66 in January next year and his wife, Janis, was also due to retire.
“After 43 years on the council it’s time that someone else got the opportunity to represent the people of Sighthill/Gorgie – and I want to do other things with my life before it is too late.”
As convener of Lothian Region and then the Capital’s Lord Provost, Cllr Milligan spent 13 years as the public face of Edinburgh.
He represented the city around the world and hosted visits by international leaders to the Capital.
He presented Nelson Mandela with the freedom of the city at a private ceremony in an Edinburgh hotel during the Commonwealth Heads of Government meeting in Edinburgh in 1997.
He was awarded France’s top honour, the National Order of Merit, and later named an Ambassador of the Auld Alliance by civic leaders in Paris at a ceremony featuring ladies from the famous Moulin Rouge.
But he famously refused a CBE from Tory Prime Minister John Major, saying at the time: “The only thing I would accept from the Conservatives is their resignation.”
His high profile also landed him in controversy. He was criticised in 1998 for swigging from a bottle of Buckfast in the street to celebrate Hearts’ first Scottish Cup victory in 42 years. One letter writer to the Evening News branded his behaviour “disgraceful” but others rallied to support him.
And he found himself in trouble over an interview in which he talked about the bargains he and his wife picked up on a four-day Christmas shopping trip to New York. Edinburgh traders, battling to win festive custom after a tough year, were less than impressed.
He has been a strong supporter of Edinburgh’s big events, including the Festival and the Military Tattoo, and is a special fan of the Jazz Festival.
First elected to Edinburgh District Council in May 1974 at the age of 23, he later switched to Lothian Region and went on to become its convener for six years. After the move to single-tier local government, he served two terms as Lord Provost. By the time he stood down in 2003, he was Britain’s longest-serving civic leader.
He said: “I have had a fantastic time, but everything has a life.
“I was probably the youngest person to be elected a councillor when I first got in, I was the only person to be convener of Lothian Region and Lord Provost of Edinburgh and I’m the only person since we’ve had democracy to be Lord Provost twice, so I’ve crammed a lot in.
“I’ve had a wonderful time – but nothing is forever and I feel it’s now time for someone else to come forward.
“It’s nothing to do with the current travails of the Labour Party, it’s all to do with the number of birthdays I’ve had.”
He said he had not yet planned what he wanted to do after retirement.
“There’s plenty time to think about that – but I’ll do what I’ve always done, which is enjoy life to the full.”
Labour group leader Andrew Burns said Cllr Milligan would be missed.
He said: “I was very sorry indeed to hear from Eric that he doesn’t intend to stand for the council next year. He is one of the longest-serving councillors in Scotland with over 40 years of public duty, including two terms of office – from 1995-96 through to 2003 – as the Lord Provost of Edinburgh.
“His sheer depth of experience, and encyclopaedic knowledge of the Capital, will be very sorely missed at the council.
“At a ward level, Eric has also been a staunch advocate for the local area which he has represented for several decades.
“I’m sure I speak for both his constituents, and fellow councillors, in thanking Eric for his many years of service, and wishing him all the very best for the future.”
Liberal Democrat group leader Paul Edie, who will also stand down next year, said Cllr Milligan had always displayed a real passion for the Capital.
He said: “Eric has given long and loyal service to the city. He is a big character and was a strong ambassador for Edinburgh abroad. When you speak to people, everyone knows Eric.
“And he had world statesmen trotting through his door – Mikhail Gorbachev, FW de Klerk. He has an immense personal love for and loyalty to the city and that shines through.
“He also has a deep knowledge of the history of the city, which adds credibility to his speeches.
“He has become a fixture. The City Chambers will be a quieter and less colourful place without him.”