Barnet pupils were in for a surprise when they bumped into a politician on the Tube.

Pupils from Whitefield School were en route to the Mayor of London’s Count on Us Challenge and were shocked to bump into the man himself!

Not only did Sadiq Khan pose for a selfie with the schoolchildren, but also joined with them in a Twitter exchange to wish them well at the event.

Mr Khan replied to the school’s tweet: “Great to meet the @Whitefield_NW2 team!

“Hope you did well and enjoyed the competition.”

The maths competition were travelling to takes place every Spring in partnership with the Mayor’s office and the Jack Petchey Foundation, and sees children in Years Eight and Nine taking part in various London-based maths puzzles and equations.

The challenge is designed to build pupils’ confidence in mental arithmetic and problem-solving.