DUP leader Sir Jeffrey Donaldson said there was a “bubble” at the Agreement 25 conference at Queen’s University Belfast.

The conference to commemorate the 25th anniversary of the Good Friday Agreement took place from Monday to Wednesday and saw speeches from former and current political leaders on the history and future of the deal.

A panel on Tuesday featured leaders of the five main political parties, the exception being the DUP, which were represented by MLA Emma Little-Pengelly.

At times during the panel discussion, audience members at Queen’s made their opposition to the DUP’s stance clear, loudly applauding points made by other party representatives when they criticised the Stormont boycott.

Speaking at Belfast City Airport after arriving back from London, Mr Donaldson said there was “realism” in London that was not evident at the conference.

“I think the mood in London is rather different from the Queen’s University bubble that we’ve seen for the last few days,” he said.

“There is a realism in London that frankly there isn’t at the event at Queen’s – a realism that we need to sort this out, that whilst we’ll have lots of people who will tell us what the problem is, I haven’t heard anyone come forward with a solution.”

The party leaders panel also touched on potential reform of the Good Friday Agreement.

Alliance leader Naomi Long said stability can only be achieved at Stormont if the Good Friday Agreement institutions are reformed to remove the ability of the biggest unionist and nationalist parties to veto governance.

Mr Donaldson said the Alliance party wants to “abandon” cross-community consensus.

“Except, of course, those who want to exclude unionists, who think the answer is to abandon cross-community powersharing, especially the Alliance party.

“Frankly, I think it’s amazing after 25 years that the so-called bridge builders are in favour of abandoning cross-community consensus in Northern Ireland.

“That’s not for the DUP. We believe that’s the way forward, it gives us the solid foundations for the restoration of Stormont and that’s what we need to get.”

Sir Jeffrey also responded to European Commission president Ursula von der Leyen’s statement that the Windsor Framework is a “gateway to a bright future”.

“It’s a pity that the gateway has bars and locks on it and checks and all kinds of things that we need to see removed if Northern Ireland is going to have unfettered access to our own internal market,” he said.

“That’s simply all we’re asking of our own government: to respect the integrity of its own internal market, to stand up for the union, to be the Prime Minister for all of the United Kingdom.

“I think the Prime Minister will respond to that; I am hopeful that what we will hear from the Prime Minister is something more positive and forward looking, something that is more inclusive than what we heard yesterday from the Secretary of State.”

At the conference, Northern Ireland Secretary Chris Heaton-Harris said a restoration of the Stormont institutions is the surest way to secure the region’s place in the UK.

Sir Jeffrey said Mr Heaton-Harris’s approach was “entirely counterproductive”.

“If Chris Heaton-Harris thinks that berating unionists on a public platform of this nature is going to find the solution that we need to get Stormont restored, then I think someone should take him aside and give him a lesson in peace building and in quiet diplomacy,” he said.

“Because that’s the way we’re going to resolve these issues, not shouting from platforms at each other. Put away the megaphone and let’s sit down with the Government and unionists, and other parties for that matter too, and let’s sort out these problems.

“That’s where the solution will be found; it will be found in those quiet conversations that enable us to get to the solution we need to see Stormont restored.

“That’s what we want.”