Proposed sanctions against Scottish Anglicans for accepting gay marriage are not strong enough, conservative leaders are claiming, in the first sign of disputes that may mar next week's summit of Church leaders in Canterbury.

Leaders from around the worldwide Anglican Communion will meet for five days to discuss religious persecution, climate change and the refugee crisis as well as their own deep divisions over sexuality.

'Consequences' are expected to be imposed on the Scottish Episcopal Church which would see them barred from representing the 80-million strong Communion on formal bodies or voting on decisions relating to policy or teaching.

The same 'consequences' were handed to the US Episcopal Church at the last summit in January 2016 after they passed gay marriage in 2015.

But conservative primates will push for stronger punishments, Christian Today understands. In an indication of the north-south divide within the Communion, traditionalist primates largely from Africa and South America will demand those from the USA, Scotland and Canada are not invited to next Lambeth Conference in 2020 – a landmark gathering of Anglican bishops every ten years.

Leaders from the powerful conservative grouping GAFCON say the 'consequences', which the Archbishop of Canterbury insists are not punishments, are not effective and have not been imposed, with figures from the US Episcopal Church playing a full part in an Anglican meeting in Lusaka later that year.

'From our perspective the sanctions have not been strong enough,' a GAFCON source told Christian Today.

'If this meeting just repeats what happened last time [when the primates met in January 2016], then what happened in 2008 [when African bishops boycotted the last Lambeth Conference and set up a rival meeting] will happen again.

'If they do so the credibility and the authority of that meeting will be diminished.'

Justin Welby personally spoke to every head of the 39 Anglican provinces over the summer to assure them the 'consequences' have been imposed to the best of his ability.

Despite this three of the 39 primates will boycott next week's gathering in protest at what they see as increasing tolerance towards gay relationships.

Earlier this week the heads of the Human Sexuality Group, which represents almost half the Church of England's general synod, wrote to all the primates urging them to tackle LGBTI discrimination in their own countries and saying the CofE was becoming more gay-friendly.

'The direction of travel for the Church of England is clearer than ever,' the letter tells the primates.

'There are inevitably those who would like to deny these measured steps towards the full inclusion of all within the Body of Christ, but their voices are becoming fewer,' they write.

Giles Goddard, the group's chair, said: 'The status quo is no longer an option — people are deeply concerned about the impact on our mission to the nation of the Church's current stance towards LGBTI people.'