Counting in the European election will resume in Northern Ireland later today with officials facing heavy criticism over the length of time the process has taken.

One MP branded yesterday's 15-hour plus count a "disgrace and a complete shambles" after it was suspended close to 1am this morning with only one of three candidates having been declared elected.

Sinn Fein's Martina Anderson emerged victorious after the first round of counting but further stages under the single transferable vote method failed to identify the other winners and the remaining candidates were left to await their fate overnight.

Fellow outgoing MEP Democratic Unionist Diane Dodds should also re-book her ticket to Brussels after notching more than 131,000 first preferences, but the celebrations had to be put on ice last night.

The third incumbent MEP Jim Nicholson of the Ulster Unionists is favourite to secure the other of the two vacant seats but is facing competition from the SDLP's Alex Attwood and the Traditional Unionist Voice's Jim Allister.

Mrs Dodds' husband Nigel, who is North Belfast MP and DUP deputy leader, was scathing of the Electoral Office for Northern Ireland, which was also criticised after delays plagued the 2011 Assembly election count.

"I think it is a disgrace that once again the Electoral Office has operated things here at a count which has made Northern Ireland look a complete shambles in terms of counting votes," he said.

"There is absolutely no reason under the sun this shouldn't be done and dusted long before now and completed and the fact is, it seems to me, the Electoral Office simply hasn't put on enough staff. They never seem to do that."

Mr Dodds added: "There is frustration amongst all parties about just how long this is taking and about the fact everywhere else in Europe has finished a long, long time ago and I just can't believe that we are once again in this situation in a Northern Ireland election and I think it does diminish democracy.

"People are entitled to have these votes declared in a timely and efficient way and it really does bring us into disrepute when it doesn't happen."

Chief electoral officer for Northern Ireland Graham Shields said the particular way the count had developed, with the requirement to recount all Mrs Anderson's ballots in order to distribute her surplus, had not been anticipated.

He insisted lack of counting staff was not the issue, noting that 270 had been employed.

"We knew we were here for a long day and we potentially expected to be here if we needed to be into the early hours of the morning but I don't think anybody could have reasonably foreseen that a count would have run into two days, for 24 hours," he said.

Mr Shields said the episode underlined the need for electronic vote counting in Northern Ireland.

"The electronic counting process, in my opinion, is an absolute necessity for going forward because none of us want to be here for days on end," he said.

Mrs Anderson was able to celebrate her achievement long before the counting controversy developed.

She insisted she had never taken her favourite tag in the election for granted.

"I am very honoured and proud that almost 160,000 people throughout the north have voted for myself," she said.

The former Stormont junior minister hailed her party's success as it was poised to take four seats across the island.

"For the first time every voter in Ireland is going to be represented by Sinn Fein," she said.

Sinn Fein president Gerry Adams was among those cheering his party colleague's victory north of the border.

"It's a good day for Sinn Fein but I also think it's a good day for the people of the island," he said.

"We will now hopefully have more conversations, more discussion, more debate about citizens' rights, about a united Ireland and about the peace process."