The Foyle MLA said that it has taken parties too long to come to that realisation.
He said: “I’m glad to hear that Sinn Féin is moving to the position that I have been outlining for some time.
“Their initial reaction to my suggestion that calling for a border poll with no plan or idea on how it would be delivered would be madness was entirely negative.
“Indeed, they have spent months attacking SDLP members for that view.
“It has taken time, as these things often do, but I’m glad that Sinn Féin leaders are now coming to the SDLP position.
“People across this island are alive to the constitutional change that is unfolding in front of us.
“The Scottish people are about to embark on a new conversation about independence, it is likely that Boris Johnson will soon be the British Prime Minister.
“Old political certainties and old majorities are no more. On an island of many political minorities, the only option is to build a broad coalition for change.
“Scottish Independence campaigners compiled a 600 page manifesto outlining what health services, schools, the economy and investment would look like in their new Scotland.
“They built a vibrant coalition across classes, creeds and backgrounds.
“And even then, they fell just short. Irish Nationalism must learn that lesson.
“We must now put in the hard yards to persuade our friends and neighbours that their interests are best served in a reconciled and prosperous new Ireland. We must spill our sweat to create that vision.
“No one party can shape that vision of a New Ireland.
“I have previously proposed the re-establishment of the New Ireland Forum post Brexit to secure a broad investment from all parties.
“It remains the best way to produce a blueprint for unity.
“Let the conversation that we’re about to have be based on what’s best for people. Let it be a cross-community conversation on a vision for the future that reflects where we are and where we want to be.
“That’s the challenge that lies ahead,” added the SDLP leader.