Anger over the Brexit deal for Northern Ireland could “definitely creep over into violence”, a group associated with loyalist paramilitary groups has warned MPs.

One member of the Loyalist Communities Council told the committee that the Northern Ireland Protocol negotiated by Boris Johnson was not compatible with the Good Friday Agreement, which underpins the peace process.

And the group’s chairman, David Campbell, said that anger in the unionist community over the border in the Irish Sea created by Mr Johnson’s deal was stronger than at any point since the 1985 Anglo-Irish Agreement which gave Dublin an advisory role in the governance of the North.

Representatives of the LCC, which was founded in 2015 by organisations links to the three main loyalist paramilitary groups, were giving evidence to the House of Commons Northern Ireland Committee just days after a controversial meeting with Brexit minister David Frost, the architect of the protocol.

Mr Campbell said that Lord Frost had told them the European Commission should hear their concerns, but added that EU negotiator Michel Barnier and Commission vice-president Maros Sefcovic had so far refused to meet them.

The LCC chairman said that he had been arrested for taking part in protests against the Anglo-Irish Agreement, just as young members of the protestant community were now being arrested at protests against the protocol.

He told the committee there was a “deep sense of hurt and anger right across the Unionist community”.

“I’ve never witnessed such anger since 1985 when the Anglo-Irish Agreement was imposed,” said Mr Campbell. “And I thought, particularly with the 25 years I’ve spent actually trying to build peace and build relationships on this island, that the days of imposition had gone.”

Asked if there was a danger of anger spilling over into violence, Mr Campbell said: “I think we definitely could creep over into violence. I have described this as probably the most dangerous situation for many years. But I do hope common sense will prevail.”

Another member of the LCC, Joel Keys, told the committee he could not rule out the use of violence, telling MPs: “There are certainly certain circumstances where violence is the only tool you have left… The minute you rule violence out completely, you’re admitting you are not willing to back up anything you believe in with anything really important.”

Mr Campbell told the committee that he regarded Dublin’s warnings during Brexit negotiations that a hard border would increase the risk of violence as effectively amounting to “threatening the resumption of a bombing campaign along the border”.

He insisted he was not threatening a resumption of violence, but told the committee: “We are not in the business of issuing threats but we are in the business of issuing warnings.”

Leading loyalist and LCC member Jim Wilson was asked if he felt “betrayed” by the Northern Ireland Protocol.

He replied: “Absolutely. We’re being left as a part of the United Kingdom inside an economic Europe with no say and not not being able to deal with anything, because our government has given that away because it was the easiest road to go down.

“As a loyalist, I believe what they’ve done as well is they have made an easier route to union in Ireland, because we’re economically tied into the Irish Republic and the EU. That makes it far easier for the next steps.

“So I believe that I have been betrayed… You can’t have both, you can’t have the protocol and the Good Friday Agreement. I withdrew my support for the Good Friday Agreement simply because it was not allowed for us to have a say in what our future is.”

Mr Campbell called on the Republic of Ireland to “join the effort to rectify this protocol”, adding that this may have to involve foreign minister Simon Coveney “falling on his sword (as) the chief architect of this mischief”.

He said that he would like to see Brussels, London and Dublin together agree to invoke Article 16 of the protocol, which allows one side to suspend elements of the border arrangements if they are found to cause significant economic, societal or environmental difficulties.

“Is the peace process not much more important than the Northern Ireland Protocol?” he asked.

“The starting point has to be the realisation that – however well-intentioned it may have been – the Northern Ireland Protocol isn’t acceptable to both communities here.

“Therefore I suspect one of the solutions might be for Europe and the United Kingdom, with the support of the Irish government, to collectively agree to trigger Article 16, to pause the protocol completely and allow a period of dialogue to find a workable solution.”