Geoff Smith, 37, beat the European record of 101 days - set by his mother - at midnight on Monday.

Geoff Smith: A once in a lifetime experience

He told BBC Radio 5 Live he was delighted to have recaptured the honour for his family - and that he was staying underground for 150 days to beat the world record of 141 days.

But the Guinness Book of Records will not recognise the feat, saying it does not want to encourage dangerous stunts.

Asked if he would do it again in the event of his achievement being overtaken, Mr Smith replied firmly: "No. It's a once in a lifetime experience."

The BBC's Daniel Boettcher: "Geoff has stayed in touch with a TV and mobile phone"

Mr Smith, of Mansfield, Nottinghamshire, was buried in the garden of the Railway Inn on 29 August in a 7ft long wooden box.

The pub landlord, Hartley Hughes, has organised a celebration party for friends and family.

"He's doing well because from day one we've done it as a stepping stone, we've set targets by the week, by the fortnight, by the month.

"The next stepping stone is to 20th December which is Geoff's birthday."

Mr Hughes explained that Geoff was fulfilling a lifetime dream.

"When his mother did it, he was seven years. He's now 37 and for last 30 years it's been his ambition to go and bury himself in a box," he said.

'My mother would be proud'

The world record was set by an American in 1981 and Mr Smith said he was looking forward to enjoying a late family Christmas when he emerges from the ground at the end of January.

He has a few small luxuries in his "coffin" - a television, a personal stereo and a little plastic Christmas tree.

Speaking through an air tube inserted in the box, he said: "I am very pleased to have reached this day. My mother would be proud of me."

He said he was well but having trouble sleeping as he uses up very little energy.