British humanists have criticised the government's new guidelines for teaching religion in schools as "misleading" and in "error".

The British Humanist Association (BHA) is demanding that Education Secretary Nicky Morgan explain why her department is running the risk "of spreading unlawful teaching practice".

The latest confrontation comes after a group of humanist parents went to the High Court to challenge the government's decision to drop the teaching of non-religious world views from schools. Although the court ruled in their favour, the Education Department has not changed the syllabus because it says the court decision was made on a technicality.

In his letter sent to Education Secretary Nicky Morgan this week, Andrew Copson of the BHA insists that failure to include non-religious world views such as humanism is unlawful, and could be pursued with legal action.

Last month, the association circulated guidance produced by legal experts on the ruling, in response to teachers and parents who wanted to know more.

The association is now querying the department's response to that guidance which they say "runs the risk of spreading unlawful teaching practice."

The High Court ruling in favour of three humanist parents and their children who challenged the relegation of non-religious world views in the new subject content for GCSE Religious Studies states that religious and non-religious world views such as humanism must be afforded equal respect.

However, the department has stated both that "the judgment should not be taken as having any broader impact on any religious education curriculum" and that "it is not for the BHA to issue legal guidance to schools."

The department also published its own interpretation of the High Court ruling.

According to a commentary by human rights professor Satvinder Juss, this guidance is "likely to mislead schools".

Copson said, "Last year's High Court judgement was clear that in order for RE to meet the legal need for neutrality, impartiality, and pluralism, non-religious worldviews must be afforded equal respect to religions in the curriculum.

"In declaring otherwise, the Government risks encouraging schools and others to act unlawfully, and schools and others responsible for RE who rely on the DfE perspective in this matter are relying on the same perspective that led to the DfE being defeated in court last year.'

The Department for Education told Christian Today it stood firmly by its dismissal of the humanists' case.

A spokesman said: "We have issued clear guidance for all schools. This guidance remains correct. We are clear that the British Humanist Association document has no official status and is inaccurate."

The department added that the Judicial Review of the Religious Studies GCSE was based on "a narrow technical point" and added: "We strongly believe the judgment has no broader impact on any religious education curriculum or the RS GCSE subject content in either faith or non-faith schools."