Prime Minister David Cameron stunned pupils at a Hendon primary school when he made a surprise visit on the day his government introduces a new national curriculum.

Children at St Mary’s and St John’s CE School gasped as the Conservative leader, joined by an entourage of security staff and advisers, dropped in on a special school assembly this morning.

Mr Cameron’s visit to the Prothero Road school comes on the day Education Minister Michael Gove announces his new national curriculum, due to be introduced in September 2014.

The new framework includes the introduction of fractions for five-year-olds and a bigger focus on ICT education in primary schools.

The Prime Minister spoke to the young students this morning and took questions during their assembly before taking a tour of the school and visiting an ICT lesson.

Staff did their best to maintain a normal school day but excited faces could be seen pressed up against classroom windows as the Tory leader made his way through the school.

Joining him on the tour was his special adviser on education Laura Trott, Hendon MP Matthew Offord and a number of invited press, including the Times Series.

St Mary’s and St John’s is in the early stages of a major expansion which includes the building of a secondary school and sixth form.

The changes will make it the first state-owned school in Barnet to provide education for young people from the ages of three to 18.

Speaking during the assembly, Mr Cameron said: “Schools provide the foundation for everything in life. I think your plan to set up a new secondary school is brilliant and we as a government support it.”

Mr Cameron urged the pupils to “set your goals and strive to achieve them” before sparking a round of applause for the “hard working staff” and wishing the children luck with their futures.

Before he left, Mr Cameron caused a stir among a number of bewildered parents when he dropped in on the infant school’s sports day taking place on the field outside.

Staff at the school were told late last week a government minister would be making a visit, but the identity of the special guest was a surprise to most in the building until Mr Cameron walked through the assembly hall doors this morning.

Headteacher Dee Oelman, who has been with the school since 2001, said: “It is fantastic for the children to actually meet the person leading the country.

“For him to show such an interest as well gives them a real boost. It is an absolute pleasure to have him here and I think it is an affirmation of the hard work all of the staff put in.

“It is inspiring for the children when the Prime Minister himself is telling them to reach their goals. It is a special day for the school and for him to be so supportive of our expansion means the world.”