The number of pupils in grammar schools in England has grown by 11,000 in the past eight years, it has been reported.

If the trend continues, there could be the equivalent of 24 new grammar schools by 2021, compared with 2010, government data reportedly suggests.

The BBC, which conducted the analysis of Department for Education figures, said they showed grammar schools had been growing even before receiving new expansion funds.

However, pupil numbers in all secondaries have begun to expand because of the birth rate and the analysis did not provide a comparison with expansion in non-selective schools. 

There is a ban on building new grammar schools, and new expansion now being funded by government is controversial owing to concerns over access for poorer pupils.

The education secretary, Damian Hinds, has said he will rely on grammar schools that choose to expand to be “true to their word” and admit more disadvantaged pupils.

The government has earmarked millions of pounds to allow selective schools in England to create more places.

It was announced in March that £50 million will be channeled into creating more grammar school places, with ministers arguing that the move will give parents more choice.

The government insisted that grammars that bid for the cash - available in 2018-19 - will have to submit plans setting out the action they will take to boost the numbers of poorer pupils they admit.

However, the move was seen by many as a revival of Theresa May’s pledge to expand selective education.

An analysis last month looked at expansion bids from 35 grammar schools and found that more than 5,000 additional selective places - the equivalent of seven new grammars - would be introduced if they were all successful.