There has been speculation ever since his dramatic 1992 general election defeat that Mr Patten, now a European Commissioner, would stage a comeback.

I don't want to hang around in politics forever

Chris Patten

A political heavyweight once tipped as future Tory party leader, the 56-year-old would take pole position in the party's centre-left if he were to return.

But asked on BBC1's Breakfast with Frost programme if he was "100%" certain he would never again seek election as an MP, Mr Patten replied: "Yes."

He went on: "This is the last public service job I will do. When I finish it, I will be 60 and I would like to enjoy my sixties as much as I can.

"I don't want to hang around in politics forever.

"I have had two or three extraordinarily interesting jobs since losing my seat, but this will be the last one."

The poignant scene as Mr Patten recieves the lowered Union flag in Hong Kong in 1997

His retirement plans include writing, making television programmes and doing some "serious gardening", he added.

Mr Patten has long been seen as a standard bearer among Tories advocating European engagement and his decision will disappoint like-minded Tories.

Before becoming a European Commissioner, he was governor of Hong Kong for its 1997 handover to China.

He also headed the commission that considered the future of policing in Northern Ireland, set up as part of the Good Friday Agreement.

Its report led to legislation - criticised on both sides of the province's political divide - which is about to be implemented.