A group of Anglican bishops has split with some of the church's top leaders to declare support for the current version of the same-sex marriage bill before Parliament, publicly calling on lower house MPs to resist the conservative push to insert stronger religious protections.

The House of Representatives will begin debating the bill drafted by Liberal senator Dean Smith on Monday and is expected to pass it by the end of the week. If it passes unchanged it will then be signed into law, and same-sex weddings will occur within weeks.

However Coalition conservatives are set on amending the bill, which passed the Senate 43 votes to 12 last week, without change. If they manage to get enough support for their changes around freedom of religion and conscience the bill will have to return to the Senate.

As Prime Minister Malcolm Turnbull confirmed he would support some of those changes in a bid to guard against any "unintended consequences", seven Anglican bishops wrote to all lower house MPs to show not all religious leaders believe amendments are necessary.

Organised by the Bishop of Wangaratta, John Parkes, the bishops say Senator Smith's bill should be approved as it stands.

"It preserves the fabric of our anti-discrimination laws, which have been developed over half a century," they say. "These give expression to democratic values of equality and fairness. It also accords fulsome recognition of the religious rights and freedoms that underpin a democratic, plural and multicultural society."

The letter points to a deepening split inside the Anglican church over same-sex marriage. Read more via Sydney Morning Herald