Tánaiste Simon Coveney has said this week is going to be a really significant one for Brexit and that Ireland must "hold its nerve."
He told RTÉ's Today with Sean O'Rourke, that the Irish Government needs to stay close to both the British government, "our neighbours", and "our EU partners".
Mr Coveney added that he hopes a letter from the European Union offering assurances on the backstop to the British government will provide reassurance and clarity.
The letter, which will be issued jointly by the presidents of the European Council and Commission, will insist that there can be no renegotiation of the backstop.
The backstop is a temporary measure that people should not feel threatened by, he said. If the vote is passed in the House of Commons tomorrow evening, the ratification process could conclude quite quickly, he added.
Mr Coveney said that he agreed with British Prime Minister Theresa May that "now is not the time to focus on plan B."
Contingency planning for a no-deal Brexit continues, he pointed out, but he hopes that they will not have to be used.