Arch-conservative Anglican leaders are threatening disruption against the Church of England, less than two weeks after bishops sided with them by refusing to change its teaching on marriage.

GAFCON, a grouping of Anglican leaders, has laid out "serious concerns" with a report published last month that announced there "are no proposals" to alter the Church's view on marriage.

Although the powerful conservative lobby is "thankful" there was no change, chairman Nicholas Okoh, primate of All Nigeria, said it "the right thing for the wrong reason".

In a letter published on Tuesday in response to the CofE bishops' report, Okoh says: "They have retained the Church's traditional teaching, but because they think that holding opposite views together will eventually produce a consensus, not because it represents an apostolic boundary."

He goes on to criticise the report's encouragement of "maximum freedom" for LGBT couples within the existing laws and its call for "a fresh tone and culture of welcome and support for lesbian and gay people".

Okoh says this marks a "relaxation of church discipline" and confuses "pastoral sensitivity with a permissive church culture" which tolerates rebellious clergy.

Anglican 'primates' are Church leaders from different independent provinces across the world. Although not officially under his jurisdiction, the Archbishop of Canterbury is considered the lead primate and the "first among equals".

But Okoh issued a threat to Welby's authority and said "practical challenges to Anglican doctrine in the Church of England" affected his ability to lead the worldwide Anglican Communion.

Pointing to a previous statement he said GAFCON affiliated church leaders had "lost confidence in the Canterbury based institutions of the Communion".

He added: "'The instruments have also sent conflicting signals on issues of discipline which confuse the whole Body and weaken our confidence in them'. Sadly, despite its merits, the English House of Bishops' report has a similar effect."

Although the bishops' report was seen as largely conservative in its refusal to change the Church's teaching on marriage, a number of conservative groupings have voiced their hesitation.

Susie Leafe, director of the conservative Reform grouping, welcomed the decision and said everyone should hear from the report "the gospel of radical inclusion which leads to radical transformation, offered by Jesus Christ".

But she added there were concerns about the proposals to allow "maximum freedom" within the teaching.

"In adopting a framework which seeks to take a middle path between biblical truth and cultural sensitivities, the bishops have ensured theological incoherence and hypocrisy will prevail for the foreseeable future, with all the hurt and confusion that will cause," she said.

"In so doing they have failed in their primary pastoral duty to teach truth and drive away error."

Her concerns were echoed by Ed Shaw, a trustee of Living Out and a gay Christian who believes the Church should uphold its position on marriage. He raised worries about the the "current pastoral chaos, which hurts gay Christians like us" and urged the Church to adopt a "culture of welcome and acceptance".