Sir Jeffrey Donaldson wants to become NI first minister

Sir Jeffrey Donaldson and Edwin Poots are in the running for the DUP leadership

Sir Jeffrey Donaldson has said he will run in the next assembly election with the aim of becoming first minister, if he wins the DUP's leadership contest on Friday.

The Lagan Valley MP is vying with assembly member (MLA) Edwin Poots to succeed Arlene Foster as DUP leader.

In April, she said she would leave the post on 28 May and step down as first minister by the end of June.

Only DUP MPs and MLAs can vote, with the result expected at about 17:00 BST.

On Thursday, both candidates issued eve of poll messages.

'Leader for Northern Ireland'

In his message to colleagues, Sir Jeffrey, currently Northern Ireland's longest serving MP, said he would contest the next assembly election - due in May 2022 - which would enable him to serve as first minister if the DUP was returned as the largest party.

"I am always willing to discuss matters that are important to you," the Lagan Valley representative wrote.

"If elected leader, I will not be leading remotely from Westminster. I will be on the ground and intend to fight the next assembly election so that I can be based here.

"I would take on the role of first minister as I believe that our people not only want a leader of unionism, they want a leader for Northern Ireland."

• All you need to know about the DUP leadership race

A law which banned double-jobbing, such as working as both an MP and an MLA, came into effect in Northern Ireland in 2016.

It means if Sir Jeffrey was elected as an MLA he would have to step down as an MP and a by-election would be held for his House of Commons seat.

'Tried and tested'

In his message to MLAs and MPs, Mr Poots said leading the DUP would be his "greatest honour".

The Lagan Valley MLA, who is Stormont's agriculture and rural affairs minister, also said he had been "tried and tested over many years in political office".

Mr Poots' campaign has said if he was successful he would not take up the role of first minister.

A spokesperson said MLAs would be consulted about the ministerial team.

In his message to party colleagues, Mr Poots said his "greatest passion is working for the people of Northern Ireland" and he had a plan to "re-invigorate unionism".