The leader of the Ulster Unionist Party has apologised after wearing wireless headphones in the Northern Ireland Assembly chamber during a debate on no-confidence motions against four Sinn Féin ministers.

Jon Burrows admitted on Tuesday that he had used AirPods while the debate was winding up on Monday, explaining that he was listening back to a previous debate and drafting a social media post.

Assembly Speaker Edwin Poots said the use of earbuds in the chamber is banned, describing it as disrespectful and unprofessional to other members.

Electronic devices have been permitted at Stormont since 2012 for purposes such as electronic speaking notes and receiving messages, but their use must be discreet and not disrupt proceedings.

The only exception allowing headphones is when a member needs to hear interpretation of another member speaking in a different language.

Poots wrote to all MLAs on Tuesday reiterating the rules after initially saying he would contact the unnamed member involved.

The no-confidence motions, debated on Monday, targeted First Minister Michelle O'Neill, Finance Minister John O'Dowd, Economy Minister Caoimhe Archibald, and Infrastructure Minister Liz Kimmins over their handling of the Drumcree dispute.

The motions failed to secure the required cross-community support from a majority of both unionists and nationalists.