Mark Durkan at the SDLP annual conference in Newcastle, Co Down yesterday: 'Margaret [Ritchie] brings the best SDLP instincts to the heart of government. She is the voice of the people at that executive table'

The SDLP's new leader will be announced today after votes in the party's first ever leadership contest are counted at its annual conference in Newcastle, Co Down.

Either Margaret Ritchie or Alasdair McDonnell will be chosen to replace Mark Durkan who is stepping down after 10 years at the helm.

In his final speech as leader yesterday, Durkan praised both candidates but clearly favoured Ritchie. "When we needed someone with guile and guts to serve as our only minister in the executive, I knew Margaret was a capable choice," he said.

"Margaret brings the best SDLP instincts to the heart of government. She is the voice of the people at that executive table. The DUP and Sinn Fein may outnumber her; they may be able to outvote her; but they have yet to outmanoeuvre her."

Durkan said the SDLP must continue to strive for Irish unity. "By collectively committing to a united Ireland achieved peacefully and democratically, we can nail the recruiting lie from so-called republican dissidents that only they are pursuing unity and only violence can deliver it.

"We can ensure that a united Ireland need not be denounced as a unionist nightmare and cannot be dismissed as nationalist fantasy."

Durkan said Sinn Fein's poor performance in previous negotiations had given the DUP a veto and led to the recent political crisis.

He welcomed the Hillsborough deal but said the SDLP would have to "work through its detail or lack of it". He added: "We will work to fill the gaps. We are a party of building-up, not holding up."

The SDLP would strive to ensure "that the three highly-charged wires of policing, parades and politics are not dangerously crossed again". Durkan said people in the North were fed up with political instability and Stormont's failure to deliver on so many issues.

However, he denounced Stormont's arch-critic, Traditional Unionist Voice leader Jim Allister.

"If you don't want to back change, but instead to change back – you've got the TUV. Jim Allister – the man who takes the 'fun' out of fundamentalist."

Referring to the intensity of the race to succeed him as leader, Durkan told delegates that Ritchie and McDonnell had bombarded them with literature and been busy emailing, tweeting and texting. "Some of you have more messages in your inbox that Selwyn Black," he said, referring to Iris Robinson's 150 texts to her former political adviser Black about her lover Kirk McCambley.