In her first speech to the SDLP's annual conference as party leader, Margaret Ritchie ruled out a merger with any of the main parties in the Republic.
Addressing delegates in Belfast, she also dismissed the notion of any electoral pact with Sinn Féin for next May's Assembly elections.
The party leader said that any major merger with a big party in the Republic would effectively mean the end of the SDLP, although she said good relations continue with Fianna Fáil, Fine Gael and Labour.
She was dismissive of Sinn Féin, who compete with the SDLP for votes in Northern Ireland.
They 'use and abuse our Irish culture as a political weapon', she said, and if scratched are 'every bit as sectarian as their opposite numbers in loyalism'.
A significant element of her speech is an olive branch, probably directed towards the Ulster Unionist and Alliance parties.
She said the SDLP and fair-minded unionists could resolve the many issues that were too much for the DUP and Sinn Féin.
On the 40th anniversary of the SDLP's foundation, the energy levels at this year's party conference are noticably higher than recent years.
Several hundred delegates packed into the Ramada Hotel's huge conference venue.
