Sinn Féin is calling on the Irish Government to take a stronger position on protecting the Good Friday Agreement.
Taoiseach Leo Varadkar will meet British Prime Minister Theresa May in Brussels today.
There are concerns that the Good Friday Agreement, which is internationally recognised will have to be altered because the north will no longer be in the EU after Brexit.
Sinn Féin MEP Martina Anderson says the Irish Government needs more backbone during the negotiations.
"The Irish government needs to get a bit of backbone and say to the British government: 'This far, and no further. You need to act as a co-guarantor, as we will'," she said.
"Let's demonstrate that we're going to do that."