The Stormont Executive is threatened with a fresh crisis after Sinn Féin said it did not believe the Democratic Unionist Party (DUP) will keep a promise to deliver on Irish language legislation.
The New Decade New Approach deal, agreed in January 2020 and which restored power-sharing in the Stormont Executive, provides for legislation to create an Irish language commissioner and official recognition of the language in the North. It also provides the same for Ulster Scots.   
Some in political unionism remain uncomfortable with official status for Irish in the North. They argue the promotion of the language is being politicised by opponents, could lead to recruitment advantages for Irish speakers in the public sector – to the detriment of the unionist community – and diminish the British identity in the region.  
However, language campaigners say the political issue is around the denial of rights and exclusion of Irish speakers.
Giving Irish official status in the North is supported by Sinn Féin, the SDLP, the Alliance Party, the Green Party and People Before Profit.
Outgoing First Minister Arlene Foster is due to resign on Monday, leaving both senior parties in the North seven days to nominate her successor and a Sinn Féin deputy first minister.
DUP MLA Paul Givan was expected to take over from Mrs Foster as First Minister, but if Sinn Féin does not nominate a deputy then the Executive cannot function and a snap election could be called.
Leaders in both parties had been meeting up until Saturday as Sinn Féin called for the full implementation of the New Decade, New Approach (NDNA) deal, which restored powersharing last year.
The cultural elements of the agreement include protections for Irish and Ulster Scots, to be delivered in the form of amendments to the 1998 Northern Ireland Act.
But on Sunday a Sinn Féin source said the party has scoped out [DUP leader] Edwin Poots and our assessment is that he is being disingenuous by saying publicly that he will honour commitments agreed in NDNA.
We believe they are acting in bad faith. We do not believe they will deliver on the Irish language Act, the source said.
Our position is that the nomination for first minister and deputy first minister has to be accompanied by legislation on the Irish language.
A party source then added: Where that takes us, God only knows.
If you make agreements to go back into government, people expect you to hold to them, the source said.
It is not genuine powersharing if youre turning around and saying yes we made this agreement that was difficult for everyone and for Poots then to not meet his commitments, while saying he will meet his commitments.
He claims to be a man of his word, so we want him to implement the agreement he has made no more, no less.
Sinn Féin wants the Irish language legislation, including providing for an Irish language commissioner, passed by next spring.
Last week, Mr Poots pledged to implement legislation in this regard as quickly as possible.
Saying he would expedite the rollout of all outstanding aspects of the NDNA agreement, he stated this would be done in a timely fashion.
Ive indicated that I will ask my first minister, whoever that happens to be, to expedite all aspects of New Decade, New Approach in a timely fashion and as quickly as possible, and that is my commitment to the people of Northern Ireland, he said.
We are quite happy to fulfil those cultural amendments to the 1998 Act and we will expedite that as quickly as possible.
On Sunday, a DUP spokesman told the BBC the party leadership stands resolute to enter government, respect powersharing and get on with the job.
It is up to others to follow, the spokesman said.
We remain committed to the New Decade, New Approach agreement and want to see it implemented in all its parts.