The SDLP is fighting with the DUP for the final seat in key battleground constituencies in the Assembly election, Colum Eastwood has claimed.
He said the DUP's decision to collapse the Stormont Executive earlier this month was a "scandalous" mistake that will "come back very badly on them".
The SDLP leader also rounded on rivals Sinn Féin, accusing the republican party of being focused on "getting themselves community jobs and looking after themselves".
He said 15 years of the DUP and Sinn Féin jointly leading government had resulted in spiralling hospital waiting lists, problems with the economy and a still-divided society.
And he claimed the Alliance Party was not engaging in what he considers important discussions on creating a "new Ireland", saying they had "stepped out of that conversation".
In an interview ahead of his party's conference on Sunday, Mr Eastwood said the SDLP was "future focused".
He dismissed recent polls which suggest the SDLP is failing to gain ground and could slip from third to fifth-largest party at Stormont after May's election.
The Foyle MP expressed confidence that his party will gain seats, naming his own constituency, West Belfast, Strangford, and Fermanagh and South Tyrone as among their targets.
He told Belfast Live: "I think we've a top-class team and I think that team is going to be extremely attractive to voters right across the north and many battleground seats where we're fighting with the DUP actually for the last seat.
"I'm pretty sure people will want to choose a top-quality SDLP candidate over a DUP candidate."
Earlier this week an opinion poll by the University of Liverpool had the SDLP on 9.9%, compared to the 11.9% of first-preference votes it received in the last Stormont election in 2017.
Mr Eastwood said political commentators should "take a bit of a breath" before jumping to conclusions, pointing to how poll predictions have been wrong in the past.
"We do our own research and we're very comfortable and confident that we're going to do well in this election, that we're going to pick up seats," he said.
Mr Eastwood said the SDLP "had got tired, we'd got stale", but in his six years as leader the party has been refreshed.
"Now we have a team that I'm extremely proud of. I think it's the best team in northern politics by a mile actually," he said.
The MP added: "For 15 years the DUP and Sinn Féin have run this place, The waiting lists are still getting longer. Our young people are still leaving. The economy is not being dealt with, and our society is still divided.
"I think people want to vote for something different and the slate of candidates that we're putting in front of the electorate is the embodiment of that future focus of the SDLP we'll be providing."
Mr Eastwood said the party was "running in this election to be in government", but he did not rule out going into opposition if they are unhappy with the programme for government.
He said the party and their voters "won't be taken for granted".
Mr Eastwood described as "reckless" the DUP's decision to withdraw Paul Givan as First Minister in protest over Brexit's Northern Ireland Protocol.
He said it was nothing to do with the Irish Sea trading arrangements, but instead about positioning the DUP ahead of the election.
"That's the only reason they've done this, and it's scandalous what they've done. It's anti-democratic and I think it will turn out to come back very badly on them," he said.
"I think it's a huge mistake, playing fast and loose with the stability of our institutions."
Mr Eastwood also criticised Sinn Féin's record alongside the DUP in leading the power-sharing government, asking: "Does anybody really think that their lives have got better?"
He added: "Sinn Féin in my view are focused on themselves and on their mates and getting themselves community jobs and looking after themselves.
"We're focused on people first. That's what I think defines us."
Mr Eastwood said his party is better placed to reach out beyond their core voters and "reconcile people right across this island".
"We believe in a new Ireland as well, but our vision of that is about bringing people together, about lifting people out of poverty, about giving people opportunity," he said.
"I think we're much better placed to provide that platform to bring people together."
The SDLP leader said although he works well with Alliance, the party was not properly engaging with discussions on a "new Ireland".
He said: "I like the Alliance Party, I work with them, they're progressive. I think it's good that we have more progressives in and around Stormont and Westminster.
"But the reality is the biggest conversation that I think we've faced for many decades is coming, and it's about the future of these islands, all of them, and the island that we're living on.
"And unfortunately - and it's up to them, they can decide to do this if they want - unfortunately Alliance have stepped out of that conversation."
He said young people from all backgrounds want to be part of a "progressive a forward-looking country" within the European Union.
"That is what we can build if we build a new Ireland and do it properly," he added.
Last year the SDLP launched the New Ireland Commission, a civic forum aimed at discussing future constitutional arrangements on the island.
However, the commission has gone quiet since then. The last time it tweeted was in July.
Mr Eastwood insisted the commission's work was continuing and he believed discussion papers would be released "within the next few weeks".
He added: "We're not focused on tweeting - we're focused on doing the work."
While DUP leader Sir Jeffrey Donaldson wants to lead his party from Stormont, Mr Eastwood as a nationalist is continuing to lead his party from Westminster.
The Foyle MP said he believes it is important to have SDLP representatives at Westminister to challenge Boris Johnson's Tory government and give an alternative voice on Northern Ireland to the DUP.
He said: "It's important that we're there speaking up against what is the worst Tory government that I think we've ever witnessed and we need people there representing us.
"And you know, I'm very confident in the team that I have led by Nichola Mallon in Stormont. We work very closely together.
"It's one team in different places."
On the announcement that all children aged between five and 11 in Northern Ireland are to be offered vaccinations against Covid-19, Mr Eastwood said "parents have the right to choose for themselves".
The MP, who has two young daughters, added: "My view is the vaccines are safe, they stop the transmission largely, they reduce the transmission, they stop people getting very sick, and what we have to do is keep people out of hospitals, keep the pressure off our NHS.
"And anything that can be done to do that people in my view should do."
