Ulster Unionist leader Robin Swann has accused his unionist rivals in the DUP of “dragging unionism into the gutter”.
During a speech at Queen’s University Belfast on Thursday evening Mr Swann insisted unionism is a movement that is not owned by any one party.
He expressed concern at how unionism is now seen across the UK where the Democratic Unionists have been hitting headlines over their supply and confidence deal with the Conservative Party.
“I hear it from unionists and non-unionists alike that there is something about the tone of unionism that is being communicated nationally that they do not like,” he said.
“That has to change. After all we have been through are we really content to let the union slide through our fingers because we could not resist being snide or obnoxious to our neighbours?
“Unionism is a movement. It is not owned by one party or another. It is made up of all classes and religions and sexual orientations. Liberals and Conservatives. Capitalists and socialists.
“It is complex and it cannot be the case that one section tries to shape it to alienate others who have just as much to offer.”
Mr Swann said sectarianism, racism and homophobia have “no place in the UUP” and added that the party aim to be “strong advocates” for minority communities.
“To truly secure our place within the United Kingdom into Northern Ireland’s second century and beyond, unionism must embrace the principle of being not for sections or factions, but for all,” he said.
“When the case is made for the union, I want it to be about more than just maintaining the status quo, or coasting by on a current majority.
“I want it to be about where your jobs, welfare and healthcare are the most secure and accessible.
“I want to it be about making the case that the lives of all citizens here are better as a part of that nation - one that advances their cultural, emotional and civic well-being.
“I want to win hearts and minds. I want a unionism where even those who do not share our ultimate political aspiration do not doubt our ambition to serve them just as well in government as those who do.”
The UUP leader took a moment during his address to remember a former party colleague who was killed by the Provisional IRA in the grounds of the university.
Edgar Graham, a law lecturer at Queen’s and Assembly member for the UUP, was shot dead on December 7 1983.
Mr Swann said: “The murder of Edgar Graham chills me to the core.
“We have some shared history; we both went to Ballymena Academy and had his life not been brought to a callous end at just 29 years old, in all likelihood he, not I, would have been the second North Antrim man to lead the Ulster Unionist Party.
“I hope we never see another day like that. When a politician, a law lecturer, a human being is shot dead in cold blood by those motivated by sectarian hatred.”