The Government and the European Union have firmly rejected demands from British Prime Minister Theresa May to re-open the Withdrawal Agreement.
Within minutes of a key House of Commons vote, near identical statements were released by Taoiseach Leo Varadkar's spokesman and from the EU that the deal agreed with Mrs May in December cannot be re-opened.
“The EU position on the Withdrawal Agreement, including the backstop, is set out in the conclusions of the December meeting of the European Council. It has not changed,” said the Irish Government.
"The Withdrawal Agreement is not open for re-negotiation."
“The Agreement is a carefully negotiated compromise, which balances the UK position on customs and the single market with avoiding a hard border and protecting the integrity of the EU customs union and single market.The best way to ensure an orderly withdrawal is to ratify this Agreement,” the statement said.
“We have consistently said that we want the closest possible future relationship between the EU and the UK. A change in the UK red lines could lead to a change in the Political Declaration on the framework for the future relationship, and a better overall outcome. We will continue our preparations for all outcomes, including for a no-deal scenario,” the statement added.
In the House of Commons, MPs approved Conservative MP Sir Graham Brady's Brexit amendment, which aims to replace the Northern Ireland backstop with "alternative arrangements", by 317 votes to 301 - majority 16.
Mrs May urged her MPs to back the amendment which she says now gives her a mandate to seek to renegotiate the Withdrawal Agreement with the EU.
It was approved by 317 votes to 301, a majority of 16. The motion, as amended, was approved without a formal vote.
Following the vote, Mrs May said she intends to vote with Brexiteer hardliners and also extended a fresh invitation to meet with Labour leader Jeremy Corbyn to seek a consensus.
Having rejected her two weeks ago, he told the Commons he is prepared to meet with Mrs May to discuss the way forward.
While the House of Commons rejected Labour MP Yvetter Cooper's substantial amendment to avoid a no-deal Brexit, MPs did approve Tory former minister Dame Caroline Spelman's amendment seeking to prevent the UK leaving the EU without a deal. MPs approved the non-binding amendment by 318 votes to 310, a majority of eight.
Following the result, Mrs May said she now had a mandate to take back for further negotiations with the EU.
She said: "Tonight a majority of members have said they would support a deal with changes to the backstop combined with measures to address concerns over Parliament's role in the negotiation of the future relationship and commitments on workers' rights in law where need be.
"It's now clear there is a route that can secure a substantial and sustainable majority in this House for leaving the EU with a deal.
"We will now take this mandate forward and seek to obtain legally binding changes to the Withdrawal Agreement that deal with concerns on the backstop while guaranteeing no return to a hard border between Northern Ireland and Ireland."