The North's First Minister David Trimble is today appealing a Belfast High Court ruling that his ban on Sinn Fein ministers attending cross-border body meetings is unlawful.
The UUP leader imposed the ban in November as a sanction due to the lack of IRA decommissioning.
While Mr Justice Kerr subsequently found in favour of Sinn Fein, Trimble has not lifted the ban as he argues he is still entitled to withhold the nominations of ministers he feels are unsuitable to represent the Stormont Executive.
Today's court action begins as the Stormont cabinet prepares for its first meeting since the UUP took a hammering in the recent Westminster general elections.