The Democratic Unionist Party (DUP) has halted joint engagements between First Minister Michelle O'Neill and Deputy First Minister Emma Little-Pengelly, following unionist anger over Sinn Féin's involvement in protests that prevented an Orange Order parade from passing along the mainly nationalist Garvaghy Road in Portadown, County Armagh.

DUP leader Gavin Robinson said the decision among the party's assembly members was unanimous. He stated that there need to be political sanctions for the behaviour of Michelle O'Neill, adding that his party would not take steps that would punish the people of Northern Ireland.

On Thursday, the DUP blocked O'Neill from attending a meeting of the UK-wide National Economic Council, which was due to be attended by Prime Minister Andy Burnham and the leaders of the UK's devolved nations. Little-Pengelly also did not attend. Stormont civil servants provided some representation at the meeting.

Burnham described the absence of the first and deputy first ministers as disappointing, but said there was some representation through civil servants. He said he did not want to see Northern Ireland, Scotland, or Wales left behind as his push for regional devolution across England moves quickly.

The DUP move follows a call by Upper Bann MP Carla Lockhart for the party to remove O'Neill from office by having Little-Pengelly resign as deputy first minister. In a letter to party colleagues, Lockhart said she would take her own course if O'Neill was not removed. She stepped down from the party officer board last week.

Robinson said he hopes Lockhart will not leave the party. Lockhart said in a social media post that she will set out the path ahead early next week, adding that party political calculations are not her concern and that this was a moment for unionism.

Other DUP politicians, including assembly member Diane Forsythe, have backed Lockhart's calls for O'Neill to be removed from office. Assembly member Maurice Bradley said that removing O'Neill would not in itself require the assembly to collapse.

Sinn Féin MP John Finucane called the DUP's action an example of economic sabotage and self-harm, all because the party struggles with internal cohesion. He said it was a very important meeting that the first minister and deputy first minister should have attended.

Alliance Party assembly member Kate Nicholl said Northern Ireland not being represented at the National Economic Council meeting was disappointing and completely baffling.

Traditional Unionist Voice leader Jim Allister said the DUP's response was beyond pathetic, adding that the DUP is interested only in clinging to office, not principle. Ulster Unionist Party leader Jon Burrows described the situation as a political fudge, all choreography and no consequences, adding it would probably galvanise Sinn Féin further at the ballot box.

SDLP assembly member Matthew O'Toole said plunging the place into more political chaos is not a sensible strategic move for unionism.

Police have said they have built cases against 60 suspects in connection with the Drumcree and Garvaghy Road protests. Eighteen of those suspects have been interviewed and case files are being prepared before being submitted to the Public Prosecution Service.