By Q Radio News and Rebecca Black, PA
Sir Jeffrey Donaldson is expected to announce his intention to stand for the leadership of the Democratic Unionist Party today.
The Lagan Valley MP is not expected to be opposed following a bruising party leadership contest last month.
Nominations opened on Saturday and will close at midday tomorrow.
The next leader will be ratified by the DUP’s central executive committee on Saturday.
The current leader Edwin Poots announced his resignation last Thursday after just 21 days - setting a record for the shortest leadership term in the DUP's history.
Sir Jeffrey Donaldson is expected to announce his intention to stand for the leadership of the Democratic Unionist Party todayhttps://t.co/f6z80v4lmd
— Q Radio News (@qnewsdesk) June 21, 2021
Sir Jeffrey was narrowly defeated by Mr Poots in the previous leadership election - losing out on the top job by just two votes.
It comes following a turbulent two months for the DUP that saw former leader Arlene Foster resign after an internal heave against her and her successor Edwin Poots follow suit after he was also fatally weakened by a party revolt.
His resignation on Thursday night came after just three weeks in the post.
It was prompted by his decision to press ahead with reconstituting the Stormont Executive alongside Sinn Fein, despite a significant majority of his MPs and MLAs being vociferously opposed to the move.
First Minister Paul Givan remains in post. It is understood that he has been urged to resign when a new leader is in place.
Once Mr Givan resigns, deputy First Minister Michelle O’Neill will also be removed from her post, triggering a seven-day period during which new office holders must be nominated or a fresh Assembly election will be called.
SDLP leader Colum Eastwood has warned that the new leader of the DUP cannot be allowed to "choreograph the collapse of the institutions at Stormont".
In a statement released on Monday, Mr Eastwood said: "With the imminent resignation of their first minister, it is increasingly clear that the DUP are positioning themselves to manufacture another political crisis that will once again threaten our local institutions.
"In a desperate attempt to stabilise their own party, they are recklessly prepared to destabilise devolution.
"No political party and no government should indulge this recklessness - the vast majority of the public won't indulge it so no-one else should."
"No-one should be threatening to tear down local government in the middle of a pandemic.
"It simply wouldn't be tolerated anywhere else and people shouldn't be expected to tolerate it here."
(Sir Jeffrey is currently the DUP MP for Lagan Valley)
Sinn Fein Finance Minister Conor Murphy said his party has no demands before renominating a deputy First Minister.
There is speculation the DUP may demand action from the UK Government over the Northern Ireland Protocol before nominating a new First Minister.
Mr Murphy described the DUP as “being at a crossroads”.
“They have to decide whether they want to be in a working Executive with the rest of us on the basis that they agreed to as a party – they signed up to this – or they want to frustrate things and prevent things, and create a very difficult working arrangement and ultimately threaten the future of the institutions,” he told BBC Radio Ulster.
“We have a lot to be getting on with, we have a pandemic that is still active, we need to see that out, we have huge economic challenges ahead of us, we have public services that have been starved by years of austerity cuts and we have a responsibility on behalf of the whole of society to deliver on these issues.”
Mr Murphy denied his party had made additional demands over Irish language legislation last week to nominate Ms O’Neill as deputy First Minister.
He said the party was “staying faithful” to the New Decade New Approach deal.
“We have said we are not pushing for anything else, we want to just see the things that were agreed under NDNA implemented in the way they were agreed to,” he added.
On Monday, Paul Bell, a member of the DUP in Co Fermanagh, who dramatically announced his intention to resign from the party over the treatment of Mrs Foster, indicated he will remain in anticipation of Sir Jeffrey becoming party leader and First Minister.
He also told UTV that he wants Mrs Foster to play a “major role” in the party again.
During the last campaign Sir Jeffrey vowed to quit as an MP in Westminster to return to the Assembly and take up the role of First Minister.
If that were to happen, it would mean a Westminster by-election in Lagan Valley, a seat held by Sir Jeffrey since 1997.
One possibility is that he could seek to replace Mrs Foster as the MLA for Fermanagh and South Tyrone when she steps down.
However, with the DUP currently in such turmoil there are doubts whether the party would want to voluntarily trigger a by-election in Lagan Valley any time soon.
Sir Jeffrey’s commanding 19,000-vote majority in Lagan Valley in the 2017 general election was trimmed to 6,000 votes at the 2019 poll following a surge in support for the Alliance Party.
Another option could see Sir Jeffrey wait until just before the next Assembly election, scheduled in May 2022, before he resigns his parliamentary seat.
In that scenario he might appoint a temporary First Minister to fill the role in the interim.