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.

Senator Penny Wong is hugged by co-sponsor Senator Dean Smith after speaking on the Marriage Amendment Bill at Parliament House in Canberra. Credit:Andrew Meares

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.