The SDLP has met with Sinn Féin and the Green Party to discuss the possibility of forming an anti-Brexit alliance in the run up to the general election.
SDLP leader Colum Eastwood said a majority of pro-Brexit majority MPs cannot be sent to Westminster.
Although the Alliance party insisted it was not interested in entering into any election pacts, Mr Eastwood said he hoped to discuss the issue with Alliance leader Naomi Long.
"We are not interested in sectarian pacts. We don't do two-party pacts to keep out another party from another community.
"We are talking about reaching out to people who want to put up a challenge to Brexiteers, who want to remind Theresa May and the people in the European Union that Northern Ireland voted to remain," said Mr Eastwood at Stormont.
He added: "I have spoken to Michelle O'Neill and Stephen Agnew (Green party leader in the region) and I want to speak to anyone else interested in that conversation.
"I am disappointed (Alliance leader) Naomi Long has already rejected the opportunity for a conversation. Hopefully, we can talk these issues out.
"We don't do sectarian pacts. We do alliances against very damaging things like Brexit. We shouldn't be sending a majority of pro-Brexit MPs to Westminster."
However, Mrs Long insisted the Alliance Party "is not interested in doing pacts with anyone."
"Label it what you like but what it will do is reduce this election into yet another sectarian head count," she added.
Mrs Long also said she believed Alliance could win both south and east Belfast in the General Election.