A number have added their names to those from other religious organisations in an open letter to home secretary Sajid Javid.
The definition, which has been proposed by the All-Party Parliamentary Group (APPG) on British Muslims is: "Islamophobia is rooted in racism and is a type of racism that targets expressions of Muslimness or perceived Muslimness."
It's been adopted by the Labour Party, the Liberal Democrats Federal board, Plaid Cymru and the Mayor of London and the government will soon decide whether to take it on board.
The main concern is whether those who criticise Islam could fall foul of the new definition.
The letter, which has been signed by former chaplain to the Queen Rt Rev Dr Gavin Ashenden and former Bishop of Rochester Rt Rev Michael Nazir Ali, states: "This vague and expansive definition is being taken on without an adequate scrutiny or proper consideration of its negative consequences for freedom of expression, and academic and journalistic freedom.
"The definition will also undermine social cohesion - fueling the very bigotry against Muslims which it is designed to prevent.
"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."
Other signatories include campaign group Christian Concern and religious freedom campaigners Lord Alton and Baroness Cox.
Those outside of the Church include Richard Dawkins, the National Secular Society and Civitas.
Addressing the issue on Premier's News Hour, Dr Anthony McRoy a lecturer on Islamic Affairs said: "Even before this has been adopted we have already seen examples of the potential consequences of this definition. Street preachers have been arrested by the police for saying certain things about Islam as a set of beliefs.
"That must never be the case that in Britain, a person is arrested or prevented from expressing his opinion about any set of beliefs, whether it be Christianity, whether it be Brexit, whether it be what football team he supports."
The Prime Minister's official spokesman said: "Any hatred directed against British Muslims and others because of their faith or heritage is completely unacceptable.
"We are conscious that the APPG's proposed definition has not been broadly accepted, unlike the International Holocaust Remembrance Alliance definition of anti-Semitism before it, which was adopted by the UK Government and other international organisations and governments.
"This is a matter that will need further careful consideration."
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