The DUP has been urged to “step up” and enter a new Stormont Executive.
Alliance Party leader Naomi Long also warned Sir Jeffrey Donaldson’s party that it would be “foolhardy” to “overplay their hand” in demands for the UK Government to take action over the Northern Ireland Protocol.
MLAs returned to Parliament Buildings on Monday following a dramatic election result at the weekend which saw Sinn Fein became the largest party.
The centre-ground Alliance Party made significant gains, increasing its seat count by nine to 17, becoming the third largest party at Stormont behind the DUP.
Leading her enlarged team into Stormont on Monday morning, Ms Long told the media they were turning up for work as they had promised voters during their election campaign.
“I want us to sit down, get the negotiations under way on the programme for government and the budget, and I want to see us getting government up and running as quickly as possible,” she said.
“We’re going to see a functioning Assembly hopefully pretty soon – that will be the easier part of all of this – but to get a functioning Executive we need the DUP to step up to the plate. With power comes responsibility, and people now need to take the responsibility seriously.
“I think the DUP need to reflect on their mishandling of Brexit, on the fact they had huge influence at Westminster and overplayed their hand.
“It would be foolhardy for them to overplay their hand with devolution because that is a gamble that Northern Ireland can’t afford to take.”
Ms Long was also critical of statements by government ministers that the Northern Ireland Protocol is threatening the Good Friday Agreement and preventing formation of government at Stormont.
“What is threatening the Good Friday Agreement is the British Government not playing an open hand with the people of Northern Ireland, using and abusing the protocol as an issue to try to garner support for their own cause,” she said.
“I think it’s time for the UK Government to resume its role as an honest broker in this process, to be open and honest with the people of Northern Ireland, with the political parties about what is possible and what is not.
“Ultimately this is Boris Johnson’s baby, the protocol was birthed on his watch. There is no point in telling us now it’s a disaster – it’s up to him to provide solutions, and those solutions have to be agreed with the European Union because that is the only thing that will bring certainty and clarity that business needs.”
The Stormont Executive has been unable to fully function since February when First Minister Paul Givan resigned as part of the DUP’s efforts to force action against the Northern Ireland Protocol.
This means Sinn Fein’s Stormont leader, Michelle O’Neill, is in line to become the first nationalist or republican First Minister.
However the DUP, as the second largest party, must nominate a deputy First Minister to serve alongside her in the joint office.
Sir Jeffrey has signalled that the UK Government must act over concerns about the post-Brexit trading arrangements before his party will nominate ministers to a new Executive.
On Sunday, his party colleague, Jonathan Buckley, said: “Either the Secretary of State wants an Executive, or a protocol – he can’t have both.”
Northern Ireland Secretary Brandon Lewis will meet the leaders of the five parties which formed the last Stormont Executive in a series of meetings on Monday.
Speaking ahead of the meetings, he acknowledged that his Government has to address issues relating to the protocol.
But he urged the parties to form an Executive as soon as possible.
Tory MP Andrew Griffith, the director of policy at No 10, was asked on BBC Radio 4’s The Westminster Hour if the UK Government is prepared to act unilaterally over the protocol.
He said its ultimate preference is to “reach a negotiated settlement”, but added: “This is having a corrosive effect on politics in Northern Ireland and, ultimately, if it needs to, then no government can be neutral about the territorial integrity of this country, and Northern Ireland is part of that.”
Mr Lewis is due to have a call with Irish Foreign Affairs Minister Simon Coveney following his meetings with the parties.
“The people of Northern Ireland deserve a stable and accountable devolved government and I will continue to urge the leaders of Northern Ireland political parties to fulfil their responsibilities and form an Executive as soon as possible,” he said.
“This process must begin with the nomination of an Assembly Speaker to allow legislation to progress and address the important issues affecting the people of Northern Ireland.
“We have to address the outstanding issues relating to the Northern Ireland Protocol, and we want to do that by agreement with the EU, but, as we have always made clear, we will not shy away from taking further steps if necessary.
“However, the people of Northern Ireland need a stable and accountable government that delivers on the issues that are important to them. That is why we urge the parties to come together and form an Executive.
“I will remain in close contact with the party leaders, but it is for the parties to agree on a way forward.
“New Decade New Approach specifically introduced measures to support a process led by the parties. This is in the best interests of the people of Northern Ireland and I urge the Northern Ireland parties to work together towards a brighter future.”
The party leaders are due to meet at Parliament Buildings later in the afternoon.
