HE is in the final days of his presidency, but Bill Clinton has no intention of spending the remainder of the time with his feet up, admiring the view across the White House lawn.

Instead he has chosen to fly across the Atlantic to aid the Northern Ireland peace process. There is even speculation that he wants to continue to play a role after his term ends.

All in all, Clinton is showing a distinct unwillingness to relinquish his position as a world leader. He is candid about his feelings, telling Rolling Stone magazine that he would have been tempted to run for president for a third term if the American constitution had allowed it.

Given that he is only 54 years old - almost a teenager in statesman terms - it is hardly surprising that Clinton is reluctant to give up the trappings of public life. And despite the fact that he says he will be busy supporting wife Hillary in her new role as New York Senator, most political commentators expect him to take up some kind of high-profile job.

Clinton is just the latest example of a prominent politician refusing to shuffle off quietly when their time at the top is up. There are obvious parallels with Britain's first woman prime minister, Margaret Thatcher, who left Downing Street a decade ago, almost choking with tears after being challenged as Tory Party leader.

She may be long gone, but she has ensured that she has not been forgotten, travelling the world on lecture tours and giving her successors, John Major and William Hague, the benefit - or otherwise - of her views, particularly on Europe.

Now 75, she is not afraid of sticking her neck out, such as lending her support to former Chilean dictator General Pinochet after his arrest in Britain in 1988 - and is now writing a new book which sets out her forthright views on politics today.

Thatcher, of course, knew all about politicians who wouldn't disappear. She was haunted by her predecessor Sir Edward Heath who, bitter over his loss of the leadership, made ceaseless and sometimes savage attacks on her policies.

World leaders may find it difficult to give up the trappings of power but it seems to be just as hard for some stars and celebrities to step back from the limelight.

Crooner Frank Sinatra was famous for his reluctance to hang up the microphone for good, announcing his retirement several times only to have second thoughts.

Ol' Blue Eyes - who died in 1998 - even joined a host of stars in a version of New York, New York at a Los Angeles gala to mark his 80th birthday five years ago, despite the fact he was already very weak.

And this week, 77-year-old Formula One commentator Murray Walker was in tears when he announced that he will retire at the end of the 2001 season after 51 years in the job.

"I don't actually want to stop but I've always said that I will do so while I'm still ahead with the viewers rather than wait until there is a general belief that I'm past it," he says.

Despite his undoubted enthusiasm for the sport, there was a feeling that it was high time that the commentator - known as Walker the Talker on the Grand Prix circuit - took the chequered flag.

His gaffes over the years have only added to his fame and the affection in which he is held by the public, but he suffered furious criticism from the press after one recent mistake when he told viewers that Rubens Barrichello, the eventual winner of the Hockenheim Grand Prix, had crashed on the first bend.

Reporters questioned the suitability of a man in his mid-70s to commentate on an international sport.

But psychologist Dr Adam Joinson of the Open University, has examined the effects of celebrity and fame, and says he can understand why politicians, such as Clinton and Thatcher, and the well-known, are reluctant to just fade into the shadows.

"I think losing influence can be a colossal thing," he says of Clinton's refusal to slow down.

"If you think of people retiring from any job, they are often affected by losing influence, especially when they have been in a prominent position. When it is all taken away suddenly - such as the end of a term as president or after a general election - it leaves a big vacant hole to be filled.

"The other aspect is to do with fame. The number of comebacks by famous sports names and pop stars suggests that, despite the downsides of being well-known, fame can be addictive."

It's a dilemma Tony Blair will undoubtedly have to face. At just 47, it's difficult to move up the ladder when you are already one of the youngest premiers.

When his term of office is over, he may be still a lot younger than many members of parliament are when they enter politics for the first time.