By Cate McCurry, PA
Hundreds of people are attending a rally in Belfast calling for a second referendum on EU membership.
Campaigners from the People's Vote rally say the public deserves to make the decision over whether the British Government's Brexit deal is the right choice.
Speakers at the rally in Belfast include Dominic Grieve QC MP, the SDLP's Claire Hanna, Green Party leader Clare Bailey and MEP Naomi Long.
Ms Long told the huge crowd that gathered in Belfast's Ulster Hall that the Good Friday Agreement is under threat from Brexit.
"We all know in Northern Ireland that while Brexit is challenging for everyone, for the EU, it is an existential challenge here in Northern Ireland and a no-deal would be catastrophic," she said.
"We have to avoid that at all costs. Brexit was never a good idea.
"At a time when the main challenges that face us are global challenges, whether it's climate, security, peace, tax transparency, our lives are more connected than ever before.
"It makes no sense to withdraw from a large international influential block."
Ms Long added: "People were promised a unicorn Brexit that doesn't exist, a fantasy Brexit that we could trade with everyone without tariffs while protecting all our jobs and skills and making so much money.
"At the same time we were told we would continue to trade normally with the European Union.
"That Brexit does not exist. This Prime Minister (Boris Johnson) can't even deliver a donkey of a deal.
"Let's get the facts out there that we will be worse off as a nation."
Green Party NI leader Clare Bailey said that Northern Ireland stands to lose the most in Brexit.
She added: "I view the referendum as a bad call and an in-house fight. It was never intended to be in the interest of the people.
"I don't see it as the will of the people. We have 52% of people who voted to leave based on a campaign found to have broken electoral law and told lies and misinformed people.
"I don't see that as democratic."
The SDLP's Claire Hanna said: "The message we have to send from here is we want our stability and future back.
"This is about protecting the welfare of everyone here, including those who voted to leave.
"We need to say to those who voted to leave that we understand your concerns.
"We can end austerity or we can end Brexit but we certainly cannot do both.
"The most plausible way out of this quagmire is a second vote."
Former Tory attorney general Dominic Grieve said that Boris Johnson does not understand the difference between truth and falsehood.
He added: "We are not leaving on October 31. The House of Commons, I am pretty certain, has made it quite clear that will not happen and if he (Prime Minister) continues to follow a fantasy he will find he will be out of office.
"There is an opportunity to go back.
"It's not to disregard the result of June 2016, but to point out politely that it has no resemblance to the paradise-like conditions the leavers predicted for us.
"There is nothing undemocratic for us to go back and confirm their views. What are the leavers frightened of?
"Together we will prevail in this matter and get the outcome we seek."