A leading member of the Church of England's governing body is quitting, accusing bishops of heresy in a sign of bitter divides over same-sex relationships.

Lorna Ashworth, a staunch evangelical, cited a 'revisionist agenda' and 'heretical teaching' as she announced her resignation over the Church's increasingly relaxed approach to gay couples.

'I am no longer willing to sit around the table, pretending that we, as a governing body of the Church of England, are having legitimate conversations about mission. I refuse to be mistaken as one participating in the fanciful notion of "good disagreement",' she said in her resignation letter.

She told Christian Today there were 'completely different agendas' at work within the Church. She said her resignation was not just about sexuality but about a fundamental understanding of the gospel.

Ashworth is a longstanding and prominent conservative presence within the CofE and sits on the influential business committee that sets the agenda for the ruling general synod as well as the Archbishops' Council - a senior advisory body to the Church.

She has spoken strongly against women bishops and gay marriage in the past and her departure will be a blow to evangelicals as they perceive the CofE is drifting towards allowing some form of gay blessing or official liturgy for same-sex couples.

Ashworth is also part of the conservative group Reform and warned evangelicals were being 'squeezed out' of the Church. She said the Archbishop of Canterbury's plea for 'good disagreement' was impossible.

'I don't think we can have good disagreement about something that is about life and death,' she said.

Evangelicals are increasingly nervous about the CofE's direction after a report maintaining the status quo on the Church's ban on gay marriage was rejected by the general synod. The Archbishops of Canterbury and York called for a 'radical new Christian inclusion' following the defeat last February and promised a new teaching document based on 'a proper 21st century understanding of being human and of being sexual'.

Since then the Church backed a ban on gay cure therapies, called for bishops to investigate re-naming services after gender transition and is set to vote on whether to adopt official service to bless gay couples.

Increasingly fraught language has followed with conservative bodies plotting a breakaway Anglican church in the UK.

The Bishop of Maidstone, Rod Thomas, who is a friend and ally of Ashworth in the CofE said he was 'very sorry' she was resigning.

'She goes because she does not want to be drawn into compromise with those who seek to revise the plain teaching of Scripture. I pay tribute to her sincerity and courage,' he said.

But he added the Church's teachings are 'based squarely on the authority of the Bible and I support every effort to sustain, promote and defend this.

'For me, that means continuing to minister within the Church of England, defending its historic commitment to Scripture.'

The Archbishop of York, who jointly oversees both the general synod and the Archbishops' Council alongside Justin Welby added he was 'sad' Ashworth had resigned.

'Her prayerfulness, magnanimity, and her grasp of all matters in hand has been a great asset to us all,' he said.

'Those who elected her were of the view that she had much to give to the working of the Council, especially in the area of Renewal and Reform. However, I do not share her doubts that the Church of England will be part of God's renewal of the Christian faith in this nation.

'I am convinced that the Church of England remains faithful to the gospel of Jesus Christ and will move forward rooted in the Christian faith as we have received it. I share Lorna's passion to make disciples in all nations and her conviction that God will continue to build his Church in this nation.

'I certainly will miss her in our partnership in the Gospel.'