UKIP boss Nigel Farage says he'd allow the Irish border to stay open – but would introduce stricter controls on who could cross it if his party was in power.
Irish residents would be able to travel north but foreign nationals in the Republic would have to apply for work permits to do so, he said.
He was speaking as he brought his anti-EU message to Belfast in a bid to build support ahead of next year's European and council elections.
The party has one MLA and a councillor in the province, but Mr Farage insists there is a real hunger for a fresh approach. The Ukip leader also claimed:
* His party has support in the Republic.
* Northern Ireland has been failed by Europe, despite billions of pounds from EU grants.
* Ukip will field at least two candidates in every area at the next council elections.
He believes the party is a positive addition to the political scene.
"We are the only genuinely UK-wide political party in operation in the UK today; our Euro-scepticism is not open to question and we also have a genuinely non-sectarian approach to politics," he said. "I believe that would be a healthy injection to the Northern Irish political debate."
Mr Farage has repeatedly demanded stronger border controls to tackle the growth in immigration, but has pledged to allow free movement for Irish people between Northern Ireland and the Republic if his party held power.
"The open border with the South has been good for us, too, let's remember that," he stated.
Northern Ireland has benefited from billions in EU funding but Mr Farage, whose party is intent on pulling the UK out of the EU, insists the real costs are hidden. "Even if you have had a good run out of it, it's finished," he added.
Ukip MLA David McNarry said: "There are people down south wanting to join Ukip.
"These are not old members of the aristocracy from the Wicklow hills, these are people from Ballymun.
"They have nobody to vote for. One wants to start a branch in Dublin."
Farage on flags, frontiers and foreigners as he sets his sights on fresh territory
An edited transcript of an interview with Ukip leader Nigel Farage (NF), the party's only MLA David McNarry (DMcN) and councillor Henry Reilly (HR)
QThe DUP is sceptical on Europe, so is there a place for Ukip here? And how do you get away from the English nationalist party many see you as?
NF: Peter Robinson has made it clear that however sceptical his party are, they want to stay members of the European Union. There's a fairly big political dividing line. Also, we can sell ourselves to the electorate here as being genuinely a UK-wide party. Thirdly, we're going to be absolutely ruthless about making sure Ukip is a genuinely non-sectarian organisation, and that again is a quite distinctive approach. On the second point, England's population is 86% of the UK, we are strong there. In Wales we won one of four seats in the European Parliament in 2009. Scotland has been more difficult, but we are taking it seriously. In Northern Ireland we are not particularly big, but are growing.
QSo what are you doing in Northern Ireland? The perception is you've an MLA, a councillor and that's it.
DMcN: We've trebled our membership since I've joined, it's around 300 now.
HR: We have appointed spokespeople in each constiuency, down to a council level in areas where we are stronger.
DMcN: I run a full-time office and my email inquiries and contact levels are up at least 20% since I was an Ulster Unionist.
QSurely you have to address Northern Ireland issues and take positions on matters such as a shared future, flags, parades. What is your position on flags?
NF: We cannot engage in any behaviour seen to be sectarian. Do people have the right to march? Of course they do. Both communities need to be able to express their identities. That is very important.
QBut should the Union flag be allowed to fly for weeks and weeks around the summer? What's your view?
NF: I think if you start banning people from doing things you actually make them more popular and attractive to rebels. That would be a mistake. Isn't that why what we're doing is interesting? Because we are trying to chart a different course.
HR: We're unashamedly unionist.
QNorthern Ireland has done pretty well out of Europe. We've got the EU money, the projects. Europe has actually been pretty kind to us.
NF: Even if you have had a good run out of it, it's finished. We've let the really poor countries in now. Plus issues like democracy shouldn't be for sale. You shouldn't be bribed for the sake of a few bob.
QSo in terms of elections, what are you doing in Northern Ireland?
NF: We have a European election next year we will contest, and council elections.
HR: Eleven new councils are planned and we're going to have at least a couple of candidates in each council.
QYou talk about putting stricter border controls in place. What would you do with our border? Will you stop people from the Republic coming up?
NF: No, we're not, and there's no reason to do so from France either.
QSo you're going to pick and choose your countries?
NF: You've got to. The open border with the South has been good for us, let's remember that. But having a total open door to very poor eastern European countries?
QSo what happens to a Polish national working in the Republic for five years. They want to come and settle in Belfast. Would Ukip be okay with that?
NF: In an independent UK? No. You could come and apply for a work permit. I think the opening of the borders next year to Romania and Bulgaria is something which could lead to a seismic change in Britain.