Sir Jeffrey Donaldson has said that a fully functioning Stormont Assembly is the best way to build support for the union.
The DUP leader has been insisting that new post-Brexit arrangements have removed the Irish Sea trading border and restored Northern Ireland’s place within the UK internal market.
The party’s acceptance of the deal has seen the party return to Stormont power-sharing after a two-year boycott.
However, several prominent figures within the DUP have publicly criticised the arrangements.
Former DUP deputy leader, Lord Dodds of Duncairn, accused the British government of engaging in “an all-out PR operation” and of being “economical with the reality” in the Lords on Tuesday.
“The reality is that the deal … still retains the protocol Windsor Framework with all its inherent anti-unionist contents,” he said.
Addressing party members and supporters in Newry and Armagh, Sir Jeffrey argued that decisions made today “will either grow support for Northern Ireland or will cede ground to the enemies of the union”.
He said that the coming generations “will determine the union’s longevity” and not a parliament or court.
“As leaders of unionism, we must realise that a demographic and political shift is taking place before our eyes.
“Either we close our eyes and ignore it, or we recognise that we are no longer in a place where 70% of the population are red, white and blue British.”
Describing himself as a “proud royalist”, a member of the Grand Orange Lodge of Ireland for almost 50 years and from a family which served with the Royal Irish Regiment, he said he wore both the harp and crown “with pride as my cap badge in the Ulster Defence Regiment”.
“I value my Britishness as represented by the crown but I also value the Irish element of my identity as represented by the harp. To be Northern Irish and British is not at all a mutually exclusive thing.”
The MP said that as Northern Ireland is made of a mix of identities, people must be allowed to “feel at home whether in their Britishness, their Irishness or something in between”.
“However, the choices that we make today will heavily influence the level of support for Northern Ireland within the Union for the next generation.
“A fully functioning Northern Ireland Executive and Assembly, delivering on key issues, is the best way to build that support.
“I am glad in recent weeks, that the membership of the DUP has been steadily growing. People are joining us from all walks of life. I am in the business of winning converts and growing support for Northern Ireland within the Union.
“The same applies both at Stormont and in our national Parliament where I am determined to make a positive case for Northern Ireland and to win friends for our cause. A Unionism that turns in on itself is a unionism that offers no hope and no vision for the future.”
He added: “There are some within Unionism who seem more focused on seeking out heretics.
“That might be interesting and, for some, even fulfilling, but it is the sure and certain path to self-destruction and reducing support for our cause, rather than strengthening Northern Ireland’s place within the Union.”
The DUP leader also criticised Sinn Fein for focusing on the timing of a border poll instead of concentrating on reconciliation for “terrible deeds of the past”.
“When I hear Mary Lou McDonald or Michelle O’Neill repeat calls for a border poll, I urge them, too, to recognise the diverse identities that make up Northern Ireland.
“Rather than seeking division and alienation of those who are pro-Northern Ireland, they would be better to focus on making the economy and our schools and hospitals here a success.
“They would be better to focus on justice and reconciliation in respect of the terrible deeds of the past, rather than seek further instability with a divisive border poll.”
He criticised statements from the Sinn Féin leadership as “fantasy stuff”, and said that former Sinn Féin president Gerry Adams had predicted in 2011 that Northern Ireland would have left the UK by 2016.
He also said that in May 2022, Mary Lou McDonald called for a border poll by 2027 but months later changed to 2030, and First Minister Michelle O’Neill had called for a border poll by 2034.
“If Sinn Féin needs to throw border poll dates to the republican base, let’s not all get caught up in that game.
“Our objective must be to make Northern Ireland an economic powerhouse for the United Kingdom.
“This more than anything will secure our place in the Union for generations to come.”