In a typically idiosyncratic twist on the usual formula used by retiring politicians, the 74-year-old Labour MP said that he wanted to spend more time with his politics.
Mr Benn, who signalled his retirement at the next general election in a letter to his local constituency party in Chesterfield, stressed that he would continue to fight even harder for his ideals outside Westminster.
"Having served for nearly half a century in the House of Commons, I now want more time to devote to politics and more freedom to do so," he said.
"I have no intention of retiring and shall continue to work closely with all those, outside and inside Parliament, who want to see the Labour Party recommit itself to the causes of social justice, democratic socialism and peace."
In a parting swipe at New Labour, he said he could no longer sit in a Commons dominated by a government that backed lone parent and disabled benefit cuts, tuition fees and the bombing of Yugoslavia.
Mr Benn's parliamentary career spanned everything from attempting to remove the Queen's head from postage stamps to overseeing the launch of Concorde.
Anthony Neil Wedgwood Benn was born in 1925 at 40 Millbank, on exactly the spot now occupied by Millbank Tower, the Labour Party HQ.
First elected as MP for Bristol South East in 1950, his greatest political legacy was a three- year battle to change the law to allow heirs to peerages to renounce their titles and sit in the Commons. When he succeeded his father to the Viscountcy of Stansgate in 1960, his seat was declared vacant. He fought a by-election, won, but was barred from Parliament. Mr Benn instigated legislation to allow MPs to disclaim peerages for life and on its passage was re-elected in 1963 to his Bristol seat.
He was Postmaster General and then Technology Minister in Harold Wilson's first government in the 1960s and Secretary of State for Industry and later for Energy in the 1970s.
Harold Wilson was so infuriated by his pipe-smoking, tea-guzzling colleague with "barmy ideas" that he dubbed him "a kind of ageing, perennial youth who immatures with age."
In 1981, Mr Benn came within a whisker of beating Denis Healey for the post of Labour deputy leader and his hard-left followers provoked the Gang of Four to leave to create the Social Democratic Party.
Boundary changes in 1983 led to him losing his Bristol seat. He became MP for Chesterfield in a by-election nine months later, but caused Neil Kinnock fewer problems as the left was slowly routed.
Mr Benn may be dismissed as a Marxist relic by his enemies, but fittingly for a former minister of technology, he is one of the most computer- literate pensioners in the Commons. He uses a Sony digital video camera to back up the famous tape-recorded diary entries.
His personal archive, made up of 12 million words, cassettes, videos, CD-Roms and Digital Video Discs, will go to the British Library on his death.
Thoughts of Comrade Tony
On the media: "If I rescued a child from drowning, the press would no doubt headline the story: `Benn Grabs Child'."
On his diaries: "They are not a memoir, they are a confession. The final entry will be from St Thomas' Hospital saying `I don't feel very well today'."
On his childhood: "I met Ramsay Macdonald in 1930 when I was taken to Trooping of the Colour. He gave me a chocolate biscuit and I've looked at Labour leaders in a funny way ever since."
On his poor hearing: "It was a very hot night in Bristol and there was a heckler. I told him a few times that he should run his own meeting rather than ruin ours and then I heard what he said. It was `can we open the window'."
On socialism: "The Labour Party has never been a socialist party, but it's always had socialists in it, just as there are some Christians in the church."
On Tony Blair: "New Labour is the smallest political party that's ever existed in Britain. It has about 500 committed members. I joined the Labour Party on my 17th birthday and I intend to die in it, but not yet."