John Lowe, the owner of the AJ and R Business Centre building at the Gordon Street and Ocean Drive intersection, posted the message on the LED sign on Thursday morning.

The message from Romans 1:18-32, accompanied by today's weather forecast, says 'men do shameful things with each other' when they choose not to have sexual relationships with a woman and for their decisions will suffer the 'punishment they deserve for their wrongdoing'.

The Port News spoke with Mr Lowe who said the message, like the many religious streamers he personally posts on the sign, reflects his own opinion. He agreed that he knew it would upset some people, but was prepared to remove it when advised of the uproar it had caused.

"It's just a general message. If it's offending people I'll take it down," he said.

Laura Murphy was among several callers who phoned the Port News and Port Macquarie MP Leslie Williams' office to complain about the message's content.

"It is offensive and disgusting and should be taken down. A friend of mine had to explain to her children what it was all about on the way to school this morning," she said.

Kristy Ringe described the message as a 'hate speech' against the gay community.

"It's the most offensive and judgemental message," she said.

"Religious groups should not be allowed to display something so disheartening so publicly and not have any consequences."

The message was posted amid renewed conversation about same-sex marriage with Labor leader Bill Shorten to deliver a private member's bill on the issue with the support of his deputy leader, Tanya Plibersek.

It follows the historic yes vote in favour of marriage equality in the socially conservative Republic of Ireland.

Two of the strongest Liberal supporters of same-sex marriage have lashed Opposition Leader Bill Shorten's move to introduce same-sex marriage legislation to the Parliament next week.

Mr Shorten announced late on Tuesday that he will introduce a private member's bill designed to legalise same-sex marriage next week, a move designed to force the Parliament - and in particular the government - to address the issue.

With three same-sex marriage bills from three different parties coming before the Parliament, the Greens are calling for a cross-party meeting for the different groups to discuss a common strategy.

"The only way to achieve a common goal and secure marriage equality in Australia is to work together across party lines," Greens senator Sarah Hanson-Young said. "Love and equality is above politics."

But Queensland Liberal MPs Warren Entsch and Wyatt Roy, who are two of the most vocal supporters of the reform in the Coalition, were scathing of Mr Shorten's decision.

Mr Entsch suggested Mr Shorten's move was a ploy to distract people from the fact that "Bill has run out of questions on the budget".

He warned "you can guarantee if you drop a hand grenade, like Bill has done, you can guarantee it won't get through the Parliament".

"I spoke to the Prime Minister this week about this, in light of the Irish referendum and we have been working on a time frame. We had made a decision to do something this year," he said.

"He [Tony Abbott] said to me 'talk to like-minded individuals, come back and have a yarn to me and we will see where we go with it'. But out of left field, he [Shorten] has pre-empted his colleagues. This is nothing to do with marriage equality, this is all about Bill trying to create credibility."

Mr Entsch said he was unsure if the push for to allow Liberal MPs a conscience vote on the issue would be approved by the Liberal party room. 

"But will the PM use his position to block it? No," he said, while predicting debate in the Liberal party room over allowing a conscience vote would happen in spring.

Mr Roy said the decision to bring forward the bill by Mr Shorten was an example of "shameless politics" from the Opposition Leader.

"This is about Bill Shorten's survival, nothing else. It is so obvious and transparent, people will see it for what it is. This just should not be a partisan issue, this should be as close to bipartisan."

On Wednesday, Mr Abbott said he took the issue very seriously, adding that "there are different views inside the Parliament, inside parties, indeed, inside families as is well known in my own case. So it is an issue where the different views, the range of views need to be treated with respect".

"It's a matter that the party room will consider, as you'd expect. I'm sure at that time we'd have a very full and frank and candid and decent debate inside the party room," he said.

"But I do have to say that my absolute priority, the government's absolute priority right now and for the next few weeks will be helping small business. It will be getting our small business budget boost through the Parliament and I hope that the Labor Party is not distracted."

The Prime Minister said the Opposition Leader's private member's bill would be dealt with according to standard procedures, which means the proposed laws will be referred to the House select committee and considered.

Liberal sources told Fairfax Media that meant, in practice, the bill would not be debated urgently despite the Labor push.

Senator Hanson-Young has also proposed a bill, and plans to begin debate on her bill in the Senate in June. And Liberal Democrat senator David Leyonhjelm has introduced a "freedom to marry" bill to the upper house. 

Mr Shorten said on Wednesday he would be "shocked if the government said they wouldn't debate the issue".

"Now I get that there's an issue, some Liberals want a free vote, others don't. I get that people have different views on marriage equality. I think this is a matter though which shouldn't be partisan, you know, Labor one way, Liberal the other way. I just think Australia needs to move forward and catch up with the times," he said.

Momentum has been building in the Labor Party for the reform, with frontbench MPs including Chris Bowen, Tony Burke and Ed Husic announcing in recent weeks they now support the reform.

At least 60 of the 80 Labor MPs in the upper and lower house will vote for the bill.

Australian Marriage Equality figures show Parliament is on the brink of having enough support to legislate same-sex marriage, needing just four more votes to pass a bill in the House of Representatives. In the Senate, it is calculated a bill could pass with a majority of one. 

James Massola, Judith Ireland - smh.com.au