Pat Cullen has vowed to put “both feet forward” in her new role as the MP for Fermanagh and South Tyrone.

Once the UK’s most marginal seat – decided by just 57 votes in 2019 – there were more than 4,000 votes between Ms Cullen, the former head of the Royal College of Nursing union, and Ulster Unionist Party candidate Diana Armstrong.

Polling 24,844 votes, Ms Cullen saw off Ms Armstrong by 4,571 votes with the UUP candidate gaining 20,273 votes.

Ms Cullen increased the vote share of her predecessor, Michelle Gildernew, who polled 21,986 in 2019.

Watched on by Sinn Fein President Mary Lou McDonald and Vice President Michelle O’Neill, Ms Cullen told buoyant supporters: “I will work night and day for Fermanagh South Tyrone.”

She paid tribute to the First Minister Ms O’Neill for “putting your trust in me that I could do this”.

Ms Cullen pledged to work alongside Ms Armstrong and said: “We will continue to work together, in your role as councillor and my role as MP and that’s what we will do, as that is what we set out on this journey to do.”

In her concession speech, Ms Armstrong appealed to the new MP to “recognise the pains that have been revisited in recent weeks”.

During an interview on BBC Radio Ulster’s Good Morning Ulster in the lead-up to the election, Ms Armstrong challenged Ms Cullen to condemn the 1987 Enniskillen bomb which claimed 12 lives and the 1998 Omagh bombing in which 29 people were killed and two unborn twins.

Ms Cullen did not do so, prompting criticism from victims’ representatives.

In her speech, Ms Armstrong said: “Many people I have spoken to over recent weeks expressed the despair that in 2024, some people running for senior elected office could still not bring themselves to even acknowledge the wrongs of horrors and terrorist acts.”

Eddie Roofe, of the Alliance Party, polled 2,420 votes followed closely by Paul Blake, of the SDLP, with 2,386 votes, Gerry Cullen, of the Cross Community Labour Alternative, with 624 votes and Carl Duffy, of Aontu, with 529 votes.