One of the more unexpected political double-acts in parliament has resumed action, with Robert Hayward and Conor McGinn pushing ahead with their joint campaign to have equal marriage extended to Northern Ireland.

Lord Hayward, a Tory peer, and McGinn, a Labour MP, are at the forefront of seeking change for the one part of the UK where same-sex marriage is still excluded. Late last year, they were named politicians of the year at the Pink News Awards.

While ministers have expressed sympathy, they say the change can only be made by the Stormont assembly, which has been suspended after two years of political deadlock.

Hayward and McGinn have sought to use parliamentary guerrilla tactics, tabling parallel private members’ bills and raising the issue whenever possible. On Friday, Hayward used a debate in the Lords on extending civil partnerships to table an amendment on equal marriage.

“We cannot go on for ever saying that we cannot take action and it has to be left in the hands of Northern Ireland,” said Hayward, a former Conservative MP and business executive who entered the Lords in 2015.

One of the many notable features of their partnership is that it happened largely by accident. When Hayward and McGinn initially drew up their private members’ bills they initially had no idea what the other was up to.

In a joint interview in McGinn’s Commons office, Hayward said it began when he sought advice on his bill from parliamentary clerks: “Suddenly one of them said to me: ‘Do you know that there’s a Labour MP pursuing this as well?’”

They joined forces to begin an energetic campaign that has won them admiration and praise. When McGinn and Hayward received their Pink News award they were introduced as the “odd couple” of LGBT rights, something that greatly amuses them both.

McGinn is a Catholic, and married with children. Hayward is a long-time LGBT campaigner, and co-founder of pioneering gay rugby union club the King’s Cross Steelers. “He’s a practising Catholic, I’m a practising homosexual,” Hayward says. McGinn said: “You know there’s a lot of crossover between these people?”

The duo nonetheless stress that their different perspectives illustrate the universal nature of the subject, and how they believe the law must catch up with a fundamentally changed world.

McGinn, who comes from Northern Ireland but represents St Helens North in the Commons, remembers how one man in his home region, when asked about equal marriage, dolefully remarked: “They’re as entitled to be as miserable as the rest of us.”

He said: “The point is that if they’re making jokes about it in a village in south Armagh, it’s part of society like anything else, like football or their jobs.”

McGinn said he was introduced to the subject by married Northern Irish friends who lived elsewhere and were distraught that their status was not recognised at home.

“It’s also about being able to stand up in a place like this, and if a kid in Northern Ireland who’s struggling with their sexuality or being bullied at school says: ‘Well, you know what, at least we’ve got somebody on our side, who’s telling me that it’s all right to be what I am.’ It’s a good thing,” he says.

Hayward, who became engaged with the issue via King’s Cross Steelers players originally from Northern Ireland, accepts that their bills have almost no chance of becoming law without official help: “We’re both at the back of the queue. I’m 42nd on the list.”

The focus is therefore, he said, on finding other opportunities to bring up the subject, such as Friday’s amendment. Hayward won support from a series of peers but withdrew the plan after the equalities minister, Susan Williams, said that while she had “considerable sympathy” for the cause it remained a devolved matter.

McGinn stresses that while the pair are not “naive about the political sensitivities”, the deadlock is frustrating, especially when polling shows overwhelming local support for change.

“We’re both talking to the government, and the secretary of state has said she’s supportive of equal marriage,” he said. “But the problem is it’s two years since the assembly failed and people don’t see any prospect of it coming back, certainly in the short to medium term. They’re just a bit fed up.”

But in a period of otherwise often bitter political and cultural splits in parliament, both recognise that their campaign is cheering to many. Hayward says: “We are divided on other matters, divided on the houses we’re in, but we can work together so closely on this.”

McGinn said there were other, more unexpected benefits. “I’m told there are certain pubs in Belfast I will never have to buy a drink in again.” He adds, deadpan: “That’s no good to me whatsoever.”