Scots Tory leader Ruth Davidson was among those leading the calls after revealing today that she lobbied Northern Ireland's First Minister Arlene Foster for change last year and has also received assurances from Theresa May that the UK Government backs same sex marriage in the province.
The Tory Government's deal with the Democratic Unionist Party (DUP), which is led by Mrs Foster and opposes gay marriage, has prompted consternation among civil liberties campaigners in the UK.
Northern Ireland is currently the only part of the UK or Ireland where same-sex couples can’t marry, despite polling evidence suggesting widespread public support for equal marriage. A major march will be held in Belfast on Saturday, organised by Amnesty International, calling for change.
First Minister Nicola Sturgeon said she was "proud" to have been part of the administration which introduced the measure in Scotland.
"The debate over equal marriage in Scotland did more than just simply allow people to marry, it also helped to challenge negative attitudes that still exist today in our society towards LGBTI people and show, quite simply, that same-sex couples are just as valued as opposite sex couples," she said.
“I offer my support to those continuing the campaign for marriage equality in Northern Ireland.”
Ms Davidson, who is gay herlself and engaged to her Irish finace insisted she is "optimistic" that the measure will be introduced in the province.
"Equal marriage isn’t about one religion or country or community," she said.
"It’s much simpler than that. At its heart, equal marriage is about the people of Northern Ireland being afforded the same rights as everybody else. So as thousands march in Belfast this Saturday, I have this message for them. Change is coming. And it’s a change for the better.”
Labour leader Kezia Dugdale , also gay, said it has been "liberating and encouraging" to see the positive coverage of same sex marriage being introduced in the rest of the UK.
She added: "I’m backing the campaign for marriage equality in Northern Ireland. I know there will be opposing views on this and the debate must be conducted courteously, but I firmly believe it’s time for LGBT people across the whole of the UK to enjoy the right to marry who they want.”
Patrick Harvie co o-convener of the Scottish Green Party, added: "We must not settle for the current treatment of same-sex couples in Northern Ireland, or just accept that the prejudice of the DUP will never be overcome. Most people in Northern Ireland support marriage equality, a majority of the Assembly supports marriage equality, and we will campaign relentlessly with our friends in Northern Ireland until they achieve that goal.”
Willie Rennie, Scottish Liberal Democrats Leader, said: "Equality in marriage for everyone is a mark of a society. The world has not collapsed since we introduced it in Scotland. In fact, it has brought joy to many lives. I would urge the political representatives of Northern Ireland to embrace it too.”
The equal marriage march will take place in Belfast on Saturday 1 July, starting at Writers’ Square in Belfast at 2:30pm, culminating in a rally in front of Belfast City Hall. The march will be led by Belfast Lord Mayor Councillor Nuala McAllister, while the rally will be addressed by same-sex couples who want to be able to marry in Northern Ireland.
Patrick Corrigan, Amnesty International’s Head of Nations and Regions, said: "We welcome this strong support from Scottish political leaders for marriage equality in Northern Ireland. We hope they will continue to work to persuade their fellow politicians at Stormont and Westminster that all UK citizens should be able to marry the person they love and that the law should be changed accordingly.
“We have been overwhelmed with high-profile support from across the UK and Ireland and from around the world for our equality campaign in Northern Ireland. We vividly remember the joyful celebrations when the Republic of Ireland voted for marriage equality two years ago. It is time for couples in Northern Ireland to be able to join in the wedding celebrations.”