Labour is considering adopting a controversial definition of Islamophobia – despite warnings it could harm free speech, The Telegraph can reveal.

Prime Minister Sir Keir Starmer and Angela Rayner, his deputy, are weighing up a “range of views” about whether to introduce an agreed description of anti-Muslim prejudice.

A definition of Islamophobia would not be legally binding but organisations would be urged to adopt in a similar way to the anti-Semitism definition accepted under Theresa May in 2016.

Campaigners say the concept must be clearly codified amid rising prejudice towards Muslims, including attacks targeted at mosques in the wake of the Southport killings last week.

Critics fear it could amount to a “blasphemy law” and senior Conservatives have insisted it must not be allowed to stifle legitimate criticism of Islam.

In opposition, Labour supported the adoption of a definition of Islamophobia, drawn up by the All-Party Parliamentary Group on British Muslims, while Wes Streeting – now the Health Secretary – was its chairman.

The definition states: “Islamophobia is rooted in racism and is a type of racism that targets expressions of Muslimness or perceived Muslimness.”

Ms Rayner’s department, the Ministry for Housing, Communities and Local Government, said it was committed to tackling all forms of hatred “including Islamophobia”.

Asked if it will adopt a working definition, it said: “We will take into account a range of views and outline any updates on the Government’s position in relation to this in due course.”

The International Holocaust Remembrance Alliance’s definition of anti-Semitism, which was accepted in 2016, is used by police forces, judges and private companies.

Labour has already accepted the APPG on British Muslims’ definition internally.

It also has the backing of the Liberal Democrats – although was opposed by the Tories in government.

‘Blasphemy law via back door’

Lord Pickles, a former communities secretary, told The Telegraph: “A definition of anti-Muslim hatred or Islamophobia is a very good idea and everybody agrees it should be done.

“The problem is that there’s nothing out there that is really satisfactory. Many a minister has started out with a good intention of doing this and they’ve just found themselves completely bogged down with unexpected and unpredictable consequences.

“I don’t think this is impossible to do, I just think it’ll be quite difficult – above all, don’t rush it.”

Bob Blackman, the chairman of the 1922 Committee, said the freedom to criticise religion must be protected.

“I’m very much in favour of saying we have to outlaw anti-Muslim hatred. There is the problem of not wanting to get to a point whereby there’s a so-called blasphemy law.

“We’ve always said there should be a definition of anti-Muslim hatred. Legitimate criticism of a religion should not be considered to be outside of the law.”

In February, Kemi Badenoch, the shadow communities secretary, said the term “anti-Muslim hatred” was more appropriate to both religious freedom and the freedom to criticise religion.

Responding to the wording accepted by Labour, Mrs Badenoch added: “The definition of ‘Islamophobia’ [they use] creates a blasphemy law via the back door if adopted.”

She went on to insist the language of “anti-Muslim hatred” was both “more precise and better reflects the UK’s law”.

There has also been criticism that the suggested definition of Islamophobia is so broad that it would be difficult to enforce in practice.

Neil Basu, a former UK counter-terror chief, warned in 2019 it “risks shutting down debate” about Islam and could allow terror suspects to “legally challenge investigation” and undermine counter-terror laws “on the basis that they are ‘Islamophobic’”.

Secular campaigners also say such a law would conflate discrimination of Muslims with general criticism of Islamic theology.

Downing Street declined to comment.