Sinn Féin president Mary Lou McDonald has said she is "absolutely in agreement" with Tánaiste Simon Coveney about the backstop in Brexit negotiations.
Mr Coveney has said the policy to ensure no hard border in Ireland "is required by all of us".
"This is not about trade or economics, but about people and peace", he wrote in The Sunday Times.
"The objective of the backstop is simple - to ensure the protection of the Good Friday Agreement, the single biggest achievement we share with successive British governments.
"It is not an inconvenience but an international agreement that underpins relationships across these islands".
He also said there were "no credible alternative arrangements" put forward by anyone.
Tánaiste @simoncoveney writes in today’s Sunday Times:
“The Irish & British governments have travelled a difficult - and sometimes tragic - road together but have found a way to build a peace process based on honest partnership.
Let’s not take risks with our precious peace.” pic.twitter.com/k85BEzFXcL
— Irish Foreign Ministry (@dfatirl) February 3, 2019
It comes as the British Prime Minister Theresa May has said she will go to Brussels with a fresh mandate.
She said: "When I return to Brussels I will be battling for Britain and Northern Ireland, I will be armed with a fresh mandate, new ideas and a renewed determination to agree a pragmatic solution that delivers the Brexit the British people voted for, while ensuring there is no hard border between Northern Ireland and the Republic of Ireland."
While speaking to the Andrew Marr Show on the BBC, Ms McDonald has said there is consensus on the backstop in Ireland.
"I am absolutely in agreement with the Tánaiste - in fact, there is absolute consensus across Irish society and Irish political life as to the necessity of the backstop - it is the bottom line.
"The Tánaiste is quite correct to say that".
"Prepare for the worst scenario"
But she said there is a difference of opinion on the issue of a border poll.
"There's no point in us burying our head in the sand or imaging, or trying to wish away, a hard border or a hard Brexit.
"Should those things come to pass, the Irish State and the Irish people need to be prepared to deal with them".
"In our view, we're en-route to constitutional change in this country anyhow and a referendum.
"It's not entirely dependent on Brexit, but I take the very pragmatic view that we prepare for the worst scenario and we protect our national interests".
"The peace process is very solid, very robust - Irish people are very clear that we are only going forward, we are not going back.
"Irish interests will be a protected"
"But let me say this: it would be grossly reckless, grossly irresponsible of the Tories in government or anybody else to play games or to play a game of chicken with that process.
"And of course there would be a concern that minorities, that certain people, might take actions in those circumstances.
"But let me repeat again: we are resolute on this side of the pond, there will be no hard border, Irish interests will be a protected.
"Peace in Ireland, peace across these islands, is a precious thing, is a thing that we have built collectively.
"And shame on anybody, on any side of the argument at Westminster that would play games with that."
"And there's been... a lot of very hot air and high rhetoric around the backstop.
"The backstop is a simple, technical mechanism to protect our all-island economy and to ensure that that process that we have built together remains intact".
