The number of pupils attending private schools has reached the highest level since records began, new figures reveal.

A study by the Independent Schools Council (ISC), which represents 1,267 fee-paying schools across the UK, finds that they educated a total of 517,113 pupils in 2014, up more than 5,000 on the previous year.

It is the highest figure since the numbers were first recorded in 1974, and marks the fourth consecutive annual rise since a drop in 2010 as a result of the economic crisis. This year, the average fee rose by 3.6 per cent to pound;5,225 per term.

The figures have been published amid uncertainty over what the future holds for private schools after the general election. Labour has pledged that independent schools will be required to partner with a school in the state sector as a condition of receiving business rates relief, with shadow education secretary Tristram Hunt insisting that they should be forced to break down the “corrosive divide of privilege”.

Bursary boom

Barnaby Lenon, chair of the ISC, argued that the increase in pupil numbers was partly down to the growth of bursaries. “We’ve made a huge effort to increase the number of bursaries, and that means more families can afford to send their children to our schools,” he said.

Mr Lenon cited economic growth and the fact that independent schools were outperforming the state sector as other possible causes, adding: “Last summer, exam results in the country as a whole dipped, but for independent schools they got better. Some parents may have noticed that.”

The ISC census also finds that although only 7 per cent of all schoolchildren are educated at independent schools, the proportion doubles to 14 per cent among post-16 students.

The region that recorded the biggest increase was Wales, where there was a 4.7 per cent rise in pupil numbers compared with 2013. However, there was a 1.1 per cent drop in the South West of England.

Paul Norton, principal of King’s Monkton School in Cardiff, said: “Our entry for Year 7 this year has doubled. It is unheard of for us. We had 33 applications for 15 scholarship places. Parents tell us they are being helped by grandparents, and cutting holidays to get the best for their children.”

The research also reveals that a record 170,000 pupils received assistance with paying their fees, with schools offering pound;836 million in 2014-15, up from pound;776 million the previous year. Means-tested bursaries were awarded to 8 per cent of pupils and were worth an average of pound;8,227 per pupil per year.

Mr Lenon said schools had avoided a sharper rise in fees by raising more from additional income sources, such as franchise schools overseas, fundraising from alumni and a growing business in Easter revision courses and summer holiday camps.

Schools were also increasingly diverting money into bursaries from non-means-tested scholarship funds, he said. “They feel that giving a scholarship to someone whose parents are wealthy is unnecessary,” he added.

Hilary French, headteacher of Newcastle High School for Girls, has seen a significant increase in sixth-form pupil numbers. “We’re probably going to have the biggest sixth form we’ve ever had next year,” she said. “We’re retaining our own students and recruiting more from outside the school. It’s because people are seeing A-levels as so important.”

The census shows that of the ISC’s 1,267 member schools, 1,025 are not-for-profit, with 242 run on a profit-making basis.