Brexit undermines the Good Friday Agreement according to Sinn Fein.
The party's Pearse Doherty (pictured) says the British government is seeking to reinforce partition through its Brexit agenda.
Sinn Fein is calling on the government act in the best interests of all Irish citizens when it comes to the UK's exit from the EU.
It comes ahead of the Northern Ireland Assembly elections which will be held next week.
Deputy Doherty says concern is growing as Brexit approachs: "Brexit is becoming very very real, business people are very concerned in relation to a hard border.
"Farmers are very concerned in relation to the loss of EU supports and people are looking for leadership and Sinn Féin are providing that.
"But we also recognise that Sinn Féin won't be at the negotiating table it is the Irish Government that will be there and so they must uphold the rights of Irish citizens in the North also."