A number of protests will take place on the border tonight (January 31) to send the message that local communities rejected Brexit.
At 11pm, the UK, including Northern Ireland, will legally leave the EU.
That means the UK will no longer be represented in EU institutions and Northern Ireland's three MEPs will no longer sit in the European Parliament.
Trade negotiations will now take place which British Prime Minister Boris Johnson aims to complete within a year, however, the EU insists it will not be rushed.
Border Communities Against Brexit (BCAB) is holding a number of rallies along the border, with one at Blackion and Aghalane at 9.30pm to show its opposition to Brexit.
Protesters have been encouraged to use their mobile phones to light up the border area.
BCAB's Dermot O’Hara concluded by saying political representatives in border counties must continue to apply pressure to ensure that the Irish Government stands up for the interests of all the people in the North.