Boris Johnson apologises after giving his wife a 'backie' on his bike on the streets of London

National cycling charity CTC said he 'should have known better'

Boris Johnson unwittingly broke the law when giving his wife a lift on his bike (Ki Price/AFP/Getty Images)

Boris Johnson has apologised after giving his wife a 'backie' on his bike on a ride through the streets of London, claiming he was unaware he was breaking the law.

The Mayor of London allowed his barrister wife Marina Wheeler to sit on his bike while he pedalled it down a street late at night.

National cycling charity CTC said he "should have known better".

A video of the couple was obtained by The Sun, and shows Ms Wheeler sitting on the saddle, without a helmet and clutching a handbag, as Johnson cycles down Barlby Road in North Kensington.

But Mr Johnson's official spokesman said the mayor was "unaware that he was apparently in contravention of the Road and Traffic Act".

"The mayor wishes to apologise for offering his wife a short lived lift on the back of his bike!

"He wasn't intending to ride all the way home from North Kensington to North London with Marina on the back, rather he was attempting to transport his wife to a main road, from where they hailed a black cab for her."

The spokesman added: "As everyone knows, the mayor is a huge supporter of cycling, and an even bigger fan of the black cab trade, hence his desire to combine the two!"

His backie, while a romantic gesture, is illegal under Section 24 of the Road and Traffic Act 1998, and offenders can be fined up to £200.