The PM was happy to spend a night under the stars as a lad

The young leader-to-be left the family home to travel to London and realise his ambitions as a rock star, the Sunday Mirror reports.

The unlikely story was recounted by Mrs Blair to guests at a Downing Street reception for the homeless charity Centrepoint earlier this week.

The PM reportedly slept near Euston station in his gap year in 1971-72.

"After he left school the prime minister came down to London," a Number 10 spokesman confirmed on Saturday.

"He spent a night on a park bench before he sorted out somewhere to stay."

Shock

One guest at the function recounted to the newspaper how the room was shocked by the surprise anecdote.

"[Cherie Blair] said the charity was very close to Tony's heart because he was forced to sleep rough on a park bench when he first came to London.

"We just couldn't believe what we were hearing. Can you imagine that the prime minister used to sleep rough on a bench?" she asked.

The government's current crackdown on begging vagrants is controversial

Meanwhile, police in the capital are continuing a trial weekend rounding up vagrant beggars in London's West End, with a total of 17 arrested so far.

Westminster Council says the move is an audit of the problem's scale but shelter charity Crisis has criticised the crackdown saying it will "criminalise" the homeless.

A Conservatives party spokesman said few homeless people would feel they have much in common with Tony Blair.