The President of Sinn Féin has criticised the Conservative Party in the UK after after the House of Commons rejected Theresa May's EU Withdrawal Agreement for the second time.
Mary Lou McDonald said the outcome of the vote shows the "absolute disregard for the people of Ireland, for our rights, our economy and the Good Friday Agreement that is at the heart of the Tory Brexit agenda".
She described the revised Brexit deal as "imperfect", but added that it was the only deal on offer.
Ms McDonald also said that a no-deal Brexit would be "unthinkable for the peace process, jobs, trade and to the loss of people's rights and quality of life, particularly in border communities".
"There is now a need to intensify planning for a no-deal crash with an imperative to ensure no return to a hard border, protections of our agreements and safeguarding the rights of citizens," she said.
SDLP leader Colum Eastwood has also expressed disappointment, but said Westminster will "have to accept the backstop at some point".
He was speaking after Prime Minister Theresa May’s deal was heavily defeated in the House of Commons.
MPs voted by 391 to 242 against it, despite last minute discussions with the EU.
Mr Eastwood said: "Sooner or later, the British Parliament is going to have to support a backstop for Northern Ireland or else support no Brexit at all; there is no happy medium between these two eventualities.
"The bottom line is that the backstop, aside from scrapping Brexit entirely, is our only insurance policy against a hard border.
"Until MPs accept this reality, Article 50 should be extended to avoid us crashing out of the EU without a deal."
Meanwhile, the leader of Northern Ireland's Alliance party has called for a second Brexit referendum.
Naomi Long said: "The clearest, most coherent and most democratic route through this impasse lies with a People's Vote, including both the Prime Minister's deal and the Remain option.
"This needs to be tested in Parliament as a matter of urgency."
DUP's deputy leader Nigel Dodds said that the threat of a no-deal Brexit should be kept on the table.
Speaking to Sky News following the vote, he said: "Once you take that threat off you are bound to be offered terms which are less advantageous in the sure and certain knowledge that the other side have that you're not going to walk away.
"So, it's totally self-defeating, it's utterly counter-productive."
Earlier, the DUP said that while Mrs May made limited progress in her discussions with the EU, it was the party's view that "sufficient progress has not been achieved at this time".
In a statement, the party said it was clear that the risks remain that the UK would be unable to lawfully exit the backstop were it to be activated.
Sinn Féin deputy leader Michelle O'Neill issued a statement in response this afternoon.
Ms O'Neill said: "The EU has shown considerable patience and a willingness to facilitate a Brexit agreement that enables Britain to leave the EU without creating a hard border in Ireland, or undermining the Good Friday Agreement.
"The way to achieve that is through the Withdrawal Agreement and the 'backstop' contained within it. There can be no deviation or diminution from that position.
"The business community, the farming community, the civil service, educationalists and trade unionists have all warned in recent weeks about the dire consequences of a no-deal crash on our economy.
"The DUP continues to ignore these warnings, just as they ignore the fact that the majority of people in the north voted against Brexit in the first place.
"This blinkered strategy is reckless in the extreme. It is driving us all towards a no-deal crash that would be catastrophic."
Now that MPs have voted down Mrs May's Brexit deal, a vote will take place tomorrow on whether the UK should leave the EU without a deal and, if they reject that, then a vote on whether to ask for a limited delay to Brexit.
The UK's crisis over European Union membership is approaching its finale with an array of possible outcomes, including a delay, a last-minute deal, a no-deal Brexit, a snap election or even another referendum.
Supporters of Brexit say while the divorce might bring some short-term instability, in the longer term it will allow the United Kingdom to thrive and also enable deeper EU integration without such a powerful reluctant member.
Brexit-supporting MPs in Mrs May's party had accused her of botching the negotiations with Brussels and surrendering on the detail of the backstop which sets out what happens to the Irish border if the sides fail to find a solution.
Many Brexiteers worried that the backstop, aimed at avoiding controls on the border between Northern Ireland and the Republic, could trap the UK in the EU's orbit indefinitely.
Additional reporting Reuters