The Prime Minister made a surprise visit to St Mary's Primary in Battersea last week.

Parents apparently gasped as they saw a rather familair face leaving the main entrance of the school on Tuesday when they picked up their children.

The visit was connected to the Evening Standard newspaper's Get London Reading campaign which they rolled out at the school in October.

The campaign, organised by charity VRH (Volunteer Reading Help), have enlisted the help of 25 volunteers who will help children at the school enjoy reading.

Head teacher Jared Brading said some of the younger pupils, unsure of what the PM looked like, even swotted up just before his arrival.

He said: "Some of the younger ones weren't sure who he was so they had a quick look at the Downing Street website.

"We weren't allowed to tell anyone about Mr Cameron's visit, even parents, but every time a man approached they cheered because they thought it was him.

"You could hear some of the parents gasp as he left the school, some of them had to do a double take.

"We were approached by the Evening Standard because the reading levels at the school needed improving."

Evening Standard editor Geordie Greg and Ukrainian businessman Constantin Zhivago, who is helping fund the project, were also at St Mary's for the day.