The Government has appointed an independent expert to lead the process towards a formal definition of Islamophobia after faith leaders, academics and politicians warned that free speech could be at risk.

Imam Qari Asim, Deputy Chair of the Anti-Muslim Hatred Working Group, will spearhead the work on establishing a definition of Islamophobia after the Government rejected the one drawn up by a cross-party group of MPs last May.

The rejected APPG definition reads: "Islamophobia is rooted in racism and is a type of racism that targets expressions of Muslimness or perceived Muslimness."

This definition has been formally adopted by the Labour Party, the Liberal Democrats, the Scottish Conservatives, Plaid Cymru and the Mayor of London.

A letter of opposition to Home Secretary Sajid Javid was signed by a wide range of academics, faith leaders, journalists, politicians and campaigners, including Professor Richard Dawkins, Lord Alton, Lord Singh, Baroness Cox, Bishop Michael Nazir-Ali, gay rights campaigner Peter Tatchell, the President of Hindu Forum of Britain Trupti Patel, Christian Concern's Head of Policy Tim Dieppe, and National Secular Society CEO Stephen Evans.

They said that the APPG definition was "vague and expansive", and could have negative consequences for freedom of expression, and academic and journalistic freedom.

They also argued that harmful practices and extremism were more likely to go unreported "as a result of fear of being called Islamophobic".

"We are concerned that allegations of Islamophobia will be, indeed already are being, used to effectively shield Islamic beliefs and even extremists from criticism, and that formalising this definition will result in it being employed effectively as something of a backdoor blasphemy law," they said. 

The Government said that the process overseen by Asim would build on the definitions of Islamophobia currently being considered, "including the APPG definition." 

It said that a formal definition of Islamophobia was needed to "help strengthen our efforts against anti-Muslim hatred", but added that there were "questions" around the APPG definition that warranted "careful consideration".

Communities Secretary James Brokenshire said: "The government is wholeheartedly committed to ensuring that Muslims are not targeted for hatred, persecution or discrimination.

"Imam Asim's appointment marks a further step in helping us to achieve that goal and ensures that we develop an effective definition of Islamophobia which commands widespread support." 

Asim said: "To tackle the alarming rise in anti-Muslim sentiment, it is imperative that Islamophobia is defined.

"I am deeply committed to working across Muslim communities and with relevant stakeholders to formulate a legally robust, comprehensive and workable definition of Islamophobia.

"I am honoured to be entrusted with this role, which will have a far reaching impact in protecting British Muslims and tackling anti-Muslim hatred."