Defend Free Speech, spearheaded by the Christian Institute and the National Secular Society, opposes the government's plans to introduce Extremism Disruption Orders (EDOs), which would allow police to apply to the High Court to restrict the movement and activities of people they deem to be "extremists".
EDOs are similar to Anti-Social Behaviour Orders (ASBOs), except with extremist behaviour as opposed to anti-social behaviour.
It is currently unclear what exactly authorities would deem as extremism, however the Defend Free Speech campaign believes it could be used to stop Christians and other groups such as secular, environmental or trade union groups sharing unpopular, traditional or challenging views.
Simon Calvert, from the Christian Institute and spokesperson for the Defend Free Speech campaign, told Premier's News Hour: "I think there is in some parts of government a phenomenal ignorance about civil liberties and about religious freedom. They're talking about having a list of state-approved religious leaders.
"These ostensibly are designed to help tackle the rise of terrorism, but the problem is from what we've heard so far from the government they're going to be drafted so widely that they could actually be used to cut across the freedom of speech of all kinds of ordinary people...
"I think there is a genuine fear that Extremism Disruption Orders will be drafted so broadly you could end up with people you and I respect in the Christian community and having an EDO slapped on them."
Listen to Premier's Antony Bushfield speaking to Simon Calvert on the News Hour here:
Lord Ahmad, Minister for Countering Extremism, said: "The Government's counter extremism strategy will not restrict anyone's freedom of speech or right to practise their faith. These are two of the core values underpinning British society that extremists wish to undermine and which our strategy will seek to promote and protect.
"Our Counter-Extremism Bill will introduce measures focused specifically on protecting people from the most persistent extremist groups and individuals who promote hatred and stir up divisions within a community.
"We will use these powers in a highly targeted way to deal with a small number of individuals and organisations who we believe are the facilitators and catalysts for extremism, with strong safeguards so that the powers are only used where it is clearly in the public interest and approved by a court."
Further details will be provided following the publication of the Extremism Bill in the autumn.