Former Sinn Fein leader Gerry Adams and current leader Mary Lou McDonald were among around 300 people demonstrating on a bridge near the border town of Newry, above the motorway linking Northern Ireland capital Belfast to Dublin, capital of the Republic of Ireland.
“My commute which is currently an hour is now going to involve three border crossings each way — that’s six border crossings every day,” environmental scientist and border resident Patricia McGenity, said at the protest, organised by “Border communities against Brexit”.
Decades of unrest between Irish republicans, who want a united Ireland, and Northern Irish Protestants, who want the province to remain in British hands, ended in 1998 with the signing of the Good Friday Agreement.
But Britain’s vote for Brexit brought the agreement back into focus.
Many fear that departing the EU will result in the reimposition of a ‘hard’ or physical border with EU member Ireland that could become a target for violence.
The issue has been a key sticking point in getting a Brexit deal through Britain’s parliament.
Some protesters dressed as customs officers, while one speaker decried the “circus of chaos” at Westminster that had left the whole process still mired in uncertainty.
“They jumped in on an issue that they didn’t really think out,” potato merchant and border resident Jimmy Myers, 58, told AFP.
“They didn’t realise the border was going to cause a major problem to them.”