Father Peter Manuel is unusual in the Christian clergy; he is prepared to speak out against the plebiscite and in favour of same-sex marriage.

"I would really love ... for marriage to become something that celebrates marriage rather than celebrates heterosexuality," Father Manuel said.

The Anglican priest runs Western Australia's only service for the LGBTI community at his parish in Subiaco.

Every Sunday evening, the altar at St Andrews is adorned with the rainbow and transgender flags in a show of solidarity for a section of Christians who do not always feel comfortable in mainstream churches.

"As one lesbian couple said to me many years ago, we just want somewhere we can hold hands and it not be an issue," Father Manuel said.

"What happens is they have the struggle of trying to be people of faith in a church that seems to be anti-gay and then they have their wider community which is anti-church and anti-Christian.

"What people want is somewhere safe where they can just be themselves."

The service started 20 years ago to support parishioners during the aids crisis and it is still a safe haven for the LGBTI community.

Father Peter Manuel bless the union of Suzie (l) and Samantha Day-Davies. ( Supplied: Ian Burgess )

Suzie and Samantha Day-Davies are concerned there is a perception in the community that all Christians are opposed to same-sex marriage.

"I'm often afraid to tell my friends, particularly in the queer community that I'm Christian because they are like, don't you hate yourself because you are Christian and gay?" Samantha Day-Davies said.

"I say no I do not; I support gay marriage and I support equal rights because I believe that God is about love, not about hate."

In April, Father Manuel blessed the couple's union at a church ceremony.

Suzie (l) and Samantha Day-Davies cut their wedding cake. ( Supplied: Ian Burgess )

They were officially married two days later at the British consulate in Perth, which they were able to do because Samantha has dual citizenship.

"We wanted to get married in the sight of God, so what we consider to be our real wedding was in the church, surrounded by all our family and friends," Suzie Day-Davies said.

"We had the big dress, we had the cake, all the bells and whistles."

Suzie, 25, and Samantha, 31, have been together for about five years. When they met, it was the first time either of them had met a gay Christian.

Their marriage is not recognised on Australian soil.

They hope the plebiscite will be abandoned in favour of a free parliamentary vote.

Christian lobby group supports plebiscite

But Lyle Shelton of the Australian Christian Lobby said there had been enough bills to change the definition of marriage.

"The Parliament has said no to this over and over again and it keeps coming back all the time," Mr Shelton said.

"I think it's only fair now that it does go to the Australian people."

Suzie and Samantha Day-Davies' wedding cake. ( Supplied: Mandy Cain )

The Canberra-based ACL is not a peak body for the denominations, but has the support of church leaders, and the biggest Anglican diocese of Sydney.

"We do have terrific relationships with the leaders of the leading Christian denominations in this country and they are very supportive of wanting to preserve the definition of marriage," Mr Shelton said.

"Taking gender out of marriage and therefore gender out of parenting, it causes other things to come into focus such as the so-called 'safe schools' program where it teaches children genderless sex education.

"It's really something that has united the church across the country."

But Father Manuel said the ACL did not represent all Christians.

"They have a view of Christianity I don't agree with," he said.

"They are promoting a view of Christian faith that is diametrically opposite to what I believe Christian faith is."

Father Manuel plans to make his views clear at WA's gay pride march in November, marching with other Christians in support of marriage equality.