Unionists must continue to convince people across Northern Ireland of the benefits of the UK, DUP leader Sir Jeffrey Donaldson has warned.

Sir Jeffrey made a plea to the DUP’s “detractors” among the wider unionist movement of the need to recognise that support for the Union is not as strong among young people as it is in the older generations, adding only a “prosperous Northern Ireland” that delivers jobs and the best education will persuade younger generations.

But his party colleague Sammy Wilson signalled there was still strength of feeling on the DUP benches about post-Brexit trade arrangements, accusing the UK Government of breaking the trust of unionists and using Northern Ireland as a “sacrificial lamb”.

Lagan Valley MP Sir Jeffrey told the Commons: “It is evident that the vast majority of people in Northern Ireland continue to accept that the settled will of the people is to remain part of the United Kingdom, and that should be respected by everyone regardless of how they identify themselves.

“But I am clear: unionists, myself included, have a job to do to continue persuading people that the union is best for all. This debate this evening is welcome, but I am clear neither Parliament nor the courts will ultimately decide Northern Ireland’s future. It is the people of Northern Ireland who will decide our future within the United Kingdom.

“Our job as unionists is to continue to persuade the majority of people that they are better off in the United Kingdom.

“And I just say, with great respect, my colleagues in the wider unionism, not on these benches but out there in the wider unionism, many of them our detractors in the DUP who attack my party, who attack the stand that we are taking, because we recognise that building a Northern Ireland that works for everyone is the key to securing the Union for the future.”

He added: “A Northern Ireland that is prosperous is the key to securing the Union for the future, and those who are a minority within unionism, but who live in the days of the 1970s when Unionism had an in-built majority, Northern Ireland is changing, its demographics are changing, and you only have to look at the results of recent polling to see that.

A prosperous Northern Ireland, a Northern Ireland that delivers jobs for our young people, a Northern Ireland that ensures they have the best education and the best start in life that will deliver support for the Union

“Unionism has to recognise that amongst young people support for the Union isn’t as strong as it is amongst more senior citizens in Northern Ireland.

“It is our task to persuade our young people, the next generation, that the Union works for them, but the way we did it in 1970 is not the way we will do it now in 2024, or in 2030, or in 2034.

“It is about a prosperous Northern Ireland, a Northern Ireland that delivers jobs for our young people, a Northern Ireland that ensures they have the best education and the best start in life that will deliver support for the Union.

“That is fundamentally and vitally important.”

During the humble address following the return of the devolved institutions in Northern Ireland, Sir Jeffrey also criticised “detractors” of his party’s deal with the Government on Northern Ireland’s trading arrangements in the UK internal market.

He said: “In our seven tests we talked about fulfilling the Acts of Union while others who hadn’t bothered to read the original Acts of Union, who didn’t know what they were talking about, who seek to rewrite history, who declare themselves the champions of unionism but don’t know their facts, talked about restoring something that would mean customs checks on goods moving between Northern Ireland and Great Britain.

Sir Jeffrey added: “This is the kind of nonsense that our detractors daily pump out. They should check their facts, know their history and understand what they’re talking about.”

Fellow DUP MP Mr Wilson (East Antrim) took a more critical stance, saying: “The economic foundational importance of the Acts of Union are still being undermined, we still have goods which have to go through a red lane – 20% we’re told.”

On the Withdrawal Act, Mr Wilson said: “The EU had made it quite clear and we had a spineless Government that was prepared to bow to them, that if these arrangement are not put in place then there’ll be no deal.

“And the Government weighing up the impact that it might have on the rest of the United Kingdom and the impact it would have on Northern Ireland decided that Northern Ireland would be the sacrificial lamb.”

Elsewhere in the debate, SDLP leader Colum Eastwood told the UK Government “not to get too comfortable” with the DUP, because it might not be a “forever love”.

The MP for Foyle said: “This humble address reads like a love letter to the DUP, and I’d just caution them not to get too comfortable because I’m not sure it’s going to be a forever love.”

Mr Wilson replied: “The love letter to unionists is essential because of the trust that has been broken by a Government that was quite happy to hand Northern Ireland over to the European Union as a vassal state.”