The Irish government has appealed for “calm heads” in Northern Ireland as the Democratic Unionist party (DUP) seeks a new leader to replace Edwin Poots following his dramatic resignation after just three weeks in the role. Northern Ireland had experienced a difficult and turbulent 24 hours and needed stability, the taoiseach, Micheál Martin, said in Dublin on Friday. “It’s very important that we all work collectively on the island towards maintaining stability and calm heads, staying focused on what is important to the people within Northern Ireland.” The comments came as the DUP began the process of finding a successor to Poots, who resigned as party leader on Thursday night after a party revolt over a deal on Irish language legislation. The rebellion also undermined his protege Paul Givan just hours after Givan’s nomination as first minister, raising doubts about the stability of the power-sharing executive and assembly at Stormont. The fusing of the loyalist marching season with protests against the Irish Sea border has raised the political temperature. A protest was scheduled for Friday night in Newtownards, outside Belfast. The Loyalist Communities Council, an umbrella group for loyalist paramilitary groups, issued a statement on Friday that urged the DUP to end “concessions” to Sinn Féin even if it meant the suspension of Stormont. The statement also contained a veiled threat to the Irish government: “Until they accept and repair the damage they have created, Irish government ministers and officials are no longer welcome in Northern Ireland.” A DUP source said many colleagues wanted a smooth, swift succession to try to end the months of turmoil for the region’s biggest party. There is speculation that Sir Jeffrey Donaldson, a Westminster MP who narrowly lost to Poots in the contest to succeed Arlene Foster, will take over. Simon Coveney, Ireland’s foreign minister, said the DUP needed “space” to regroup amid a tense political climate. “We’re back to square one, if you like, where the party has to find a way of electing a new leader that can unite the DUP, or at least attempts to. And that’s important for politics in Northern Ireland,” he told RTE. The DUP’s partners in the power-sharing government were blunter in urging the party to resolve its internal ructions before the chaos infected the Stormont institutions. “The last few weeks have been a joke. It has been a real mess for unionism and a mess for all of us,” said Colum Eastwood, the SDLP leader. “The only way that we can make this place work is to work it together.” Doug Beattie, leader of the Ulster Unionist party (UUP), said there was a crisis within the DUP and its brand of unionism. “They left the goal open for Sinn Féin to score. That’s why the DUP finds itself in a degree of crisis, whether it’s imploding or just a blip, we’ll see that in the coming weeks and months.” Poots led the coup in April that unseated Foster as party leader – in large part a punishment for DUP blunders over Brexit that led to the creation of an Irish Sea border. When Foster stepped down as first minister on Monday, Poots was unable to replace her with Givan without support from Sinn Féin, which demanded a commitment on Irish language legislation. Poots assented to a deal on Wednesday night brokered by the UK government but failed to sell it to colleagues, prompting a backlash over his apparent refusal to listen as well as the concession to Sinn Féin.