Northern Ireland First Minister Paul Givan has announced his resignation from Stormont's powersharing Executive.
The move is part of the DUP's escalating protest strategy against Brexit's Northern Ireland Protocol.
Givan said the protocol had undermined a cornerstone of powersharing in Northern Ireland - governance with the consent of both nationalists and unionists.
"Today marks the end of what has been the privilege of my lifetime - to serve as the First Minister of Northern Ireland," Givan said as he announced his resignation at a Belfast hotel.
"When I first entered the Assembly 12 years ago, I never expected to have the opportunity to lead the government and serve the people of Northern Ireland as First Minister."
The announcement comes 24 hours after DUP Agriculture Minister Edwin Poots acted unilaterally to order a halt to agri-food checks required under the post-Brexit trading arrangements.
Civil servants have yet to implement the instruction and checks are continuing.
Givan's resignation automatically removes Sinn Fein deputy First Minister Michelle O'Neill from her job because, under Stormont's powersharing rules, one cannot hold office without the other.
Other Stormont ministers can remain in post but the Executive can no longer meet and is unable to take significant policy decisions.
Sinn Fein has denounced the move as an electoral stunt designed to consolidate DUP support in the face of recent poor opinion poll performances.
Givan said: "Our institutions are being tested once again. And the delicate balance created by the Belfast and St Andrews agreements has been impacted by the agreement made by the United Kingdom Government and the European Union which created the Northern Ireland Protocol.
"The consent principle is a cornerstone of the Belfast Agreement and it is my earnest desire that all sections of the community will soon be able to give consent to the restoration of a fully functioning executive, through a resolution to the issues that have regrettably brought us to this point."
There was emotion in Givan's voice as he said: ``Most of all I want to thank my family, especially my wife Emma. It's often those that we are close to in our families that feel the pressure, even more so than those of us in frontline politics It wouldn't have been possible without their support.|