SINN Fein are predicted to become the biggest party in Northern Ireland for the first time as leaders clashed over power-sharing during a televised debate.

A final poll ahead of the Stormont Assembly elections on May 5 forecast the Irish Nationalist party winning comfortably - at the expense of the Democratic Unionist Party (DUP), who were the only major local party to back Brexit.

Sir Jeffrey Donaldson, DUP leader, has been campaigning against the Northern Ireland Protocol and has repeatedly called on the UK Government to trigger Article 16, the mechanism to prevent a hard land border between Northern Ireland and the Republic of Ireland.

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Sinn Fein have said the protocol is “the answer, not the problem” and warned any unilateral action from the UK would not be acceptable.

If Sinn Fein do return the largest vote share, they will be entitled to nominate a first minister.

In the 2017 Stormont election, Sinn Fein closed the gap on the DUP with 27.9% (27 seats) of the vote, compared to the unionist party’s 28.1% (28 seats).

The Irish News predicts that in 2022, Sinn Fein will overtake the DUP for the first time and take 26.6% of the vote share, with the unionist party dropping to only 18.2%.

The National: Leaders of the five largest parties in NI took part in a live debate on BBC One Northern IrelandLeaders of the five largest parties in NI took part in a live debate on BBC One Northern Ireland

However, the Alliance Party of Northern Ireland are also predicted to increase their vote share from 9.1% in 2017 to sitting neck and neck with the DUP on 18.2% (+9.2).

Sinn Fein and the DUP are required to cooperate as a cross-party government in line with the Good Friday Agreement signed in 1998.

However, during a debate on Tuesday evening, Donaldson refused to confirm if he would accept the role as number two in the power-sharing agreement should Sinn Fein return the highest vote share following Thursday’s poll.

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The National: Donaldson refused to say if the DUP would nominate a Deputy FM is Sinn Fein return largest vote shareDonaldson refused to say if the DUP would nominate a Deputy FM is Sinn Fein return largest vote share

Donaldson was challenged to say whether the DUP will form an executive or refuse to accept their salaries if re-elected.

He reiterated his position that he will turn up on day one after the election, but will not form an executive until concerns around the Northern Ireland Protocol are dealt with.

Donaldson said the political institutions “must be sustainable”.

Sinn Fein vice president Michelle O’Neill said it would be “absolutely unfathomable” to tell the electorate that a new executive would not be formed following the election.

The National: O'Neill said it would be “absolutely unfathomable” to tell the electorate that a new Executive would not be formedO'Neill said it would be “absolutely unfathomable” to tell the electorate that a new Executive would not be formed

She also said she still has not heard if unionist leaders will “accept the democratic outcome of the election”, in a seeming reference to the poll predicting victory for her party.

Donaldson has not said if he will nominate a deputy first minister to serve along with a Sinn Fein first minister in the joint office.

O’Neill accused the DUP of “holding us all to ransom” over its position on refusing to go back into an executive without action on the Northern Ireland Protocol.

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The resignation of first minister Paul Givan in February left the executive unable to fully function.

O’Neill said: “Whilst the rest of us want to put money in the people’s pockets and deal with the cost-of-living crisis, the DUP are telling people their identity is under threat.”

The National: Givan served as First Minister of Northern Ireland from June 2021 to February 2022Givan served as First Minister of Northern Ireland from June 2021 to February 2022

Donaldson responded, pointing to the resignation of former deputy first minister Martin McGuinness which saw the Assembly collapse for three years.

He said ministers continue in their posts, while O’Neill countered saying they are “caretaker ministers”.

The leaders of the five largest parties took part in a live debate on BBC One Northern Ireland on Tuesday evening ahead of polling day on Thursday.