The Australian Christian Lobby has welcomed the decision of the Federal Coalition not to allow a free vote in Parliament on the issue of same-sex marriage during the current term.

The decision was made after a marathon six hour party room debate on the issue which ran late into the night on Tuesday.  Following the decision, Prime Minister Tony Abbott said the Coalition would see out this term supporting the traditional definition of marriage but, foreshadowing the possibility of a plebiscite or referendum on the issue, added that in a subsequent term of Parliament it is a "matter that should rightly be put to the Australian people".

Australia's Parliament House in Canberra

"Tonight's decision means all Australians remain free to speak what they believe about marriage without fear. It is so important we keep speaking without fear for the benefits of marriage and why its definition should be preserved."

- Lyle Shelton, managing director of the Australian Christian Lobby

The Australian Christian Lobby hailed the decision as a "win for the millions of Australians who will always believe it is between one man and one woman".

Lyle Shelton, the ACL's managing director, said in a statement issued after the party room decision that Mr Abbott and Coalition MPs had shown "great courage and leadership in speaking for marriage at a time when a powerful minority have made it difficult to speak".

"Tonight's decision means all Australians remain free to speak what they believe about marriage without fear. It is so important we keep speaking without fear for the benefits of marriage and why its definition should be preserved."

Mr Shelton said that while there was no doubt debate on the issue would continue, "it is important that words like 'bigot' are set aside and that the demonisation of marriage supporters now ceases".

He has criticised television networks including Channel Seven and Channel 10 for refusing to run "innocuous advertisements putting the other side of the argument".

While noting that the possibility of a referendum of plebiscite being held in the next term of Parliament would give "breathing space for ordinary Australians to be allowed to know what is at stake", in a statement issued this morning, Mr Shelton said that any referendum questions must canvass what he described as "the harms to freedom of speech, religion and conscience" which have been raised by Human Rights Commissioner Tim Wilson.

"Referendum questions must also canvass the societal consequences of intentionally creating motherless and fatherless children through controversial assisted reproduction techniques such as commercial surrogacy and anonymous sperm donation," he said. "We need to unpack what 'marriage equality' means."

Liberal MP Warren Entsch, who is expected to introduce a bill legalising same-sex marriage in this session of Federal Parliament, has told News Corp Australia that he will be crossing the floor to support the bill but conceded that he didn't think there would be enough support to see it succeed.

Mr Entsch said that following the party room meeting Mr Abbott agreed he could be involved in developing policy on the issue of same-sex marriage in the lead-up to the next election.

Opposition Leader Bill Shorten said Mr Abbott and the Liberal Party remained "stuck in the past" on the issue of same-sex marriage. He said the Labor Party would introduce a bill legalising same-sex marriage within 100 days if it took power at the next general election.