Changes to the Good Friday Agreement settlement might be required to reflect the changing electoral landscape of Northern Ireland, a former secretary of state has said.

The intervention by Brandon Lewis, who served as Northern Ireland secretary from early 2020 until last July, comes amid growing expectations that the UK and the EU are close to agreeing a deal on post-Brexit arrangements in the region.

Writing in the Telegraph newspaper, Mr Lewis said it was time to “confront difficult questions” about whether the current electoral system is reflecting the recent rise in the Alliance Party, which designates itself as neither nationalist nor unionist and has enjoyed surging support in recent elections.

“The growth in the vote for the Alliance Party underlines the feeling that many more people now want to vote on issues, not on sectarian lines.

“That should be embraced as the greatest success of the Belfast/Good Friday Agreement. But if the Agreement does not evolve further, under current rules, if Alliance and its vote share continues to grow, it will never have the right to nominate the First or Deputy First Minister.

“Democracy cannot succeed when it is set in tram lines that can never cross.”

Mr Lewis served as Northern Ireland secretary during a tricky time for politics in the region, as it grappled with the Covid-19 pandemic and disputes over the Northern Ireland Protocol negotiated by Boris Johnson.

The comments by the Great Yarmouth MP come as Downing Street hopes that a breakthrough between London and Brussels will lead to the restoration of powersharing in the region, which collapsed after the DUP walked away last year in protest at the protocol.

“The Belfast/Good Friday Agreement was, however, written in such a way that it could evolve. We must be honest about the fact that it was a brilliant framework for peace but is proving a poor foundation for effective government,” he wrote.

“The question we must dare to ask ourselves is: what next? How can the Agreement be evolved to better support effective and resilient government for all the people of Northern Ireland? How must the structure of Stormont be reinforced so that it is not so fragile?

“People deserve accountable politicians and a resilient devolved government that is able to deliver on the issues that matter to them, rather than the sporadic governance of recent years.”

His proposals, which did not come with any specific details, echo similar calls from the Alliance Party which finished third in the Assembly elections last May.

Alliance leader Naomi Long has previously mooted reforms of the post-Good Friday Agreement institutions to reflect changes in Northern Ireland.

Mr Lewis said that a debate on reform must wait amid the current crisis, but should happen “this year”.

“Yet all these questions must wait. It is difficult to see how we can dedicate efforts to those challenging conversations when the key issue at the heart of Stormont’s current impasse remains.

“Yet, have those conversations this year we must. It is vital for the future of our UK, and for all of us who care so passionately about Northern Ireland’s place within it.”