The Prime Minister staked a claim for credibility with the kids yesterday when he told a school class ­ in French ­ that he was really into the rock band the Darkness.

Tony Blair told children at Sacred Heart Roman Catholic Secondary School in Southwark, south London, that whenever he dipped into his children's CD collections, he went straight for the Lycra-clad Suffolk rockers.

The thought of Mr Blair air-guitaring and head-banging his way around the bedrooms in Downing Street is not one that ought to cause too much surprise. After all, this is a man who wore an open shirt, purple loons and Cuban heels, and pouted his way around university when he was a Rolling Stones and Mick Jagger-obsessed lead singer of a student rock band called the Ugly Rumours. But close observers of Mr Blair's musical tastes may detect an element of opportunism in his championing of the band that have dominated the UK album charts this year with Permission To Land. The Prime Minister, who also told the children during their French class that he loved U2 and the Foo Fighters, went on Desert Island Discs seven years ago, when he was Leader of the Opposition, and picked out a selection that was far less raucous.

Mr Blair's chosen mix of classical, folk and soft rock included Adagio for Strings, op 11, by Samuel Barber and Debussy's Clair de Lune. He also opted for the classical guitar of Recuerdos de la Alhambra by Francisco Tarrega, "Wishing Well" by Free, and "In My Life" by the Beatles.

But by far the most surprising of his selection was "Cancel Today" by the almost unknown Spanish-influenced folkies Ezio. The endorsement of Ezio ­ made up of Ezio Lunedei and Mark "Booga" Fowell ­ propelled the duo on to the front pages.

Mr Blair's musical tastes began to change after his triumphant march to No 10 to the sound of the dance anthem "Things Can Only Get Better" by D:Ream. He became the new champion of Britpop, inviting Noel Gallagher of Oasis and the Creation Records boss Alan McGee to Downing Street.

Yesterday's school visit brought back memories of Mr Blair's appearance this year at a community college in Sheffield, during which he strapped on a Fender Stratocaster and took part in a jam session with a student band called the Jabberwocker.