A Christian free-school that was at the centre of allegations that it taught creationism as a scientific theory is planning to open another school.

Grindon Hall Christian School in Sunderland, Tyne and Wear, says that high demand from parents has led it to identify a nearby site where it wants to open a new free school in September.

Principal Chris Gray told TES that the school had felt “obliged” to look into opening a new school after going through 75 appeals from disappointed parents hoping to get their children into Grindon last year, a process he described as “painful”.

But secularist campaigners have hit out against the plans, despite assurances from the school that it does not teach creationism in science.

The former private school hit the headlines in 2012 after campaigners highlighted a “creation policy” document on the school’s website, which suggested support for both creationism and evolution as valid science.

Richy Thompson, campaigns officer for faith schools and education at the British Humanist Association, which highlighted the issue at the time, told TES: “When the first [Grindon] free school opened we were concerned because this policy suggested a history of teaching creationism.

“We would be concerned about a second one opening for the same reasons.”

The Department for Education introduced new rules safeguarding the teaching of evolution in science following the controversy around Grindon and other free-school applicants that had promoted creationist views.

But Mr Gray told TES that the allegations that Grindon Hall taught creationism were “mischievous and unfounded” and parents’ fears had since been allayed over the issue.

“We have done a survey and had a very positive response ... we are considering putting in an application,” he said.

Mr Gray added that the school had the capacity to open another branch by September, although he admitted it would be “unusual” for an application to progress that quickly.

A statement announcing plans for a new free school on Grindon Hall’s website added: “Grindon Hall has been hugely over-subscribed since we opened as a free school in 2012, with four or five applications for every place.

“The new school would be part of the Grindon Hall family, run by the same people and with the same commitment to small classes, firm discipline and high expectations.”