Liberal senator James Paterson has released a new same-sex marriage bill which he says offers better protections for religious freedoms than the other bill under consideration.

Last week, it was revealed conservative members of the Coalition were putting the finishing touches on such a bill ahead of the announcement of the postal survey result on November 15.

While Senator Paterson himself is non-religious, supports same-sex marriage, and says he voted yes in the survey, deputy Labor leader Tanya Plibersek slammed his bill as a delaying tactic.

"Having one person who says they're a yes voter as the frontman for this bill doesn't hide where this bill comes from," she told RN Breakfast.

We've taken a closer look at what's inside.

What are the protections in Senator Paterson's bill?

Apart from allowing same-sex couples to marry, Senator Paterson says his bill would:

allow ministers of religion and celebrants to refuse to officiate same-sex weddings if they believe in the traditional definition of marriage

allow ministers of religion and celebrants to refuse to officiate same-sex weddings if they believe in the traditional definition of marriage allow people to refuse to participate in a same-sex wedding if that goes against their beliefs (through a "limited right of conscientious objection")

allow people to refuse to participate in a same-sex wedding if that goes against their beliefs (through a "limited right of conscientious objection") allow people to discuss their traditional view of marriage without fear of legal penalties

allow people to discuss their traditional view of marriage without fear of legal penalties allow parents to have their children removed from classes which don't reflect their views on marriage (a so-called "Safe Schools clause")

As well, Senator Paterson says the bill would stop governments and their agencies from taking adverse action against people on account of their traditional views of marriage — for instance, they wouldn't be able to withdraw funding for charities for that reason.

"All Australians should be able to live their lives according to their own values. No group should impose their values on another group," he said.

To ensure these protections, the bill would override existing state and territory anti-discrimination and freedom-of-speech laws.

Doesn't the existing bill already protect religious freedoms?

Yes, but in a narrower way.

As it stands, Liberal senator Dean Smith's bill is the one that would likely be used to legalise same-sex marriage in the event of a yes vote.

Key dates in SSM postal survey: August 24 — the final day to register with the AEC if you want to take part in the survey

September 12 — survey forms start being sent out

September 25 — all forms are expected to have been sent

October 27 — forms are strongly encouraged to be returned by this date

November 7 — the final deadline to return surveys

November 15 — results are released

It provides exemptions so that churches and religious organisations can refuse to conduct or provide services to same-sex weddings.

But Senator Paterson's bill would also protect the freedoms of other individuals and businesses — for instance, florists, cake makers and photographers.

He clarified how the bill would work, saying that it would "remain unlawful" to refuse to bake a cake for a gay couple on a birthday, as an example.

"You would have a right to conscientiously object i.e. not participate in a gay wedding," Senator Paterson told ABC's Lucy Barbour.

"I think that's an important difference because weddings are special. They are different from any other thing that happens in society. We have very strong beliefs about that."

What are the concerns about adding further protections?

Law Council of Australia president Fiona McLeod SC said Senator Paterson's bill would take us into "uncharted waters" by allowing people to refuse to provide goods and services on the grounds of "belief, thought and conscience".

"You could potentially see a situation where a hire car company could leave their customers stranded on the way to a marriage ceremony simply because the driver held a thought or belief against it. This is even if the belief had nothing to do with religion," she said in a statement.

Ms Plibersek called Senator Paterson's bill a "bridge too far".

"Are we really saying in Australia today that you can refuse to serve someone because they're gay? You can refuse to bake them a cake or drive them in your car?" she said.

But Lyle Shelton, managing director of the Australian Christian Lobby and a leading voice for the No campaign, had previously called the protections in Senator Smith's bill inadequate.

He said Senator Paterson's alternative, "makes good on the Yes campaign's promise that no other Australian's freedoms will be impacted".

Finance Minister Mathias Cormann told RN Breakfast Senator Smith's bill was a "good starting position", but added, "I suspect it will need improvement in terms of strengthening religious protections".

Which bill would likely be used in the event of a yes result?

Senator Cormann, who is also the Deputy Leader of the Government in the Senate, said the Government would not take a view on which bill to support, and would instead leave this to Parliament.

But he did note Senator Smith's bill had gone through a cross-party Senate committee process.

Ms Plibersek too noted Senator Smith's bill had broad support in Parliament, and said it should be voted on by Christmas.

"[Senator Paterson's bill] is one more delaying tactic from the people who brought you the $122-million, waste-of-money postal survey that we've just subjected the nation to," she said.

"Why should we accept one more delaying tactic from the opponents of marriage equality?"

Senator Smith told The Sunday Times he would introduce his bill to the Senate on Thursday, even if the result of the survey was no. Senator Paterson could also put forward his bill this week.