The former Archbishop of Canterbury, Lord George Carey, has attacked David Cameron over his support for marriage equality, saying many Christians feel “persecuted” over the issue.

Lord Carey claimed many Christians were left with “anxieties” over the Prime Minister’s push for same-sex marriage, accusing him of coming across as insincere in his pledges to support faith leaders.

On 20 March David Cameron held a pre-Easter Downing Street reception for Christian faith leaders, at which he said he supported their right to practise their religions and urged them to stand up to “aggressive secularisation”.

Writing for the Daily Mail, Lord Carey said: “It was a bit rich to hear that the Prime Minister has told religious leaders that they should ‘stand up and oppose aggressive secularisation’ when it seems that his government is aiding and abetting this aggression every step of the way.”

He pointed to Cameron’s push for the legalisation of same-sex marriage, which he warned would “empty marriage of its fundamental religious and civic meaning”.

Lord Carey went on to say that professions such as registrars should “expect to be sacked” if they do not back same-sex marriage, and said there was strong legal opinion that teachers would face disciplinary action if they don’t follow “the new politically-correct orthodoxy”.

The former Archbishop cited a ComRes Poll released yesterday, which revealed two thirds of Christians now believe they are a “persecuted minority”. The poll was commissioned by the Coalition for Marriage, the group that Lord Carey helped to launch to campaign against marriage equality.

He acknowledged that while “few in the UK are actually persecuted”, he felt that David Cameron had “done more than any other recent political leader to feed these anxieties”.

The poll also stated that 58% of Christians who voted for the Conservatives in 2010 said they “definitely will not” vote for the party in 2015. Three quarters of Christians polled said the government is “not listening” to them.

Aside from his attack on David Cameron, Lord Carey expressed his alarm at MP Chris Bryant’s proposal to convert the chapel of St Mary Undercroft to a multi-faith prayer room, which could potentially allow equal marriage ceremonies to take place there.

Lord Carey said the chapel would change “fundamentally” under Mr Bryant’s plans, potentially “banishing the Christian faith” from the historic site.

A Downing Street spokesman replied to Lord Carey’s concerns: “This government strongly backs faith and Christianity in particular, including backing the rights of people wanting to wear crosses at work and hold prayers at council meetings.

“Christianity plays a vital part in the Big Society, from the many brilliant church schools to the huge number of charitable causes based in churches across the country.”

The former Conservative Home Office minister, Nick Herbett, who is in a civil partnership said: “How can it be an “aggressive secularist” agenda to allow religious groups like the Quakers to conduct gay marriages when they want to? The Bill protects religious groups who don’t want to conduct gay marriages – why should they have the power to stop others who do? So what, Lord Carey, do we call the agenda of religious leaders who are trying to dictate the choices of others outside their faith?”

The Liberal Democrat MP Stephen Williams described Lord Carey’s article as an “idiotic statement.” He added that he hopes “someone buys him a dictionary and 20th century history book so he can look up persecution.”

In October 2012 Lord Carey made a speech at a rally in which he compared the opponents of equal marriage to persecuted Jews in Nazi Germany.