Legal challenges and academic debates cannot rewrite the sovereign will of the people of the United Kingdom to quit the European Union, the party's MEP Diane Dodds told the DUP annual conference.
She said at the La Mon Hotel in east Belfast on Saturday that the matter was settled and could not be altered.
“We joined as one nation in 1973 and we will leave as one nation,” she told delegates.
Ms Dodds was dismissive of suggestions that Brexit would lead to a hard Border between Northern Ireland and the Republic.
“Let me be clear - we want to see the Border remain open for business and travel. The Common Travel Area has survived a World War and decades of terrorism. It will survive our exit from the EU,” she said.
“Endless IRA terror sprees brought no hard border. So why then should there be one now?”
Ms Dodds said the DUP respected all those who saw merit in remaining in the EU. “We want to work with them to ensure that Northern Ireland’s future after our exit benefits everyone. That means working with everyone to secure the best deal for Northern Ireland - even our political opponents,” she said.
The MEP said the DUP had never wavered in its Euro-scepticism. “We voted to secure our right to make our own laws, control our own borders and spend our own money,” she said.
“Our nation has shown the aspiration and courage to chart its own course in the world, free from the shackles of Brussels. Nobody should be more proud of this moment in history than this party,” she added.
Her husband, the DUP deputy leader Nigel Dodds said his party played a crucial role in helping deliver the historic vote to leave the EU. “And we will play a crucial role in ensuring parliament delivers on the people’s decision,” he said.
