The Sinn Féin Leader Mary Lou McDonald has said a referendum on Irish unity must be held within the next five years.
Speaking during her address to the party's Ard Fheis in Derry tonight, she said Brexit has changed Ireland and people were now considering a united Ireland.
She said a referendum would happen and she said it was no longer a question of if, but rather when it would take place.
Deputy McDonald told the conference that the Government needs to convene an all-Island forum to map a transition to a united Ireland.
She told delegates that the people of Ireland had been "short changed" by Fine Gael and Fianna Fáil.
She said they needed a new deal to tackle the "crushing cost" of living and increase income.
Deputy McDonald pledged to reduce rents by up to €1,500 a year through tax relief and a three-year rent freeze.
Ms McDonald said the crisis in housing and the health service in the Republic would only be solved with Sinn Féin in government.
She accused the Government of being out of touch with rural Ireland and said the upcoming by-elections were a chance for people to have their say.
She said: "Leo Varadkar, Simon Harris, Eoghan Murphy lead one of the most out of touch governments the state has ever seen - they haven't a clue about the reality of towns and villages in rural Ireland struggling to survive."
Deputy McDonald also said Sinn Féin would only enter Government in the republic if they could deliver on housing and healthcare and on the issue of Irish unity.
She said the political stalemate at Stormont was unsustainable but she said Sinn Féin is not the obstacle to power sharing.
Deputy McDonald said Sinn Féin negotiators stand ready to enter into talks with unionists.
She said: "I challenge the DUP and both governments to step forward. To resolve the issues and get government back in action."
Earlier, Sinn Féin's leader in Northern Ireland Michelle O'Neill was returned as the party's Vice President by defeating the challenge of fellow Assembly member John O'Dowd.
Welcoming the result of the ballot, Ms O'Neill said: "I am really honoured to have been endorsed by the membership of Sinn Féin and re-elected to the position of Leas-Uachtaran.
"I am thankful to delegates and members across Ireland who voted for me in this contest.
"John is a longstanding republican and a highly regarded colleague and I very much value his political contribution and friendship.
"We are both committed to advancing our party, so that we are fit for purpose as a political movement now and in the future."
Meanwhile, Sinn Féin's Housing Spokesperson said it is now €5,000 more expensive to rent per year compared to when Fine Gael got into Government in 2011.
Eoin Ó Broin hit out at the Government's Rebuilding Ireland programme.
He told the Ard Fheis that homelessness was up 67% and there were 10,000 people homeless.
He said 4,000 children would sleep in hubs, hotels and B&Bs tonight and some would spend their fourth Christmas in emergency accommodation.
At the @sinnfeinireland Ard Fheis #SFAF19 - @moneillsf says she is "certain" a referendum on Irish unity is coming and tells delegates Taoiseach @LeoVaradkar needs to "catch up with the people - they are miles ahead of you "— Paul Cunningham (@RTENewsPaulC) November 16, 2019
Mr Ó Broin said house prices were up 20% in three and a half years meaning he said that a whole generation was locked out of the housing market.
He added that securing affordable accommodation was increasingly beyond the reach of many people.
Mr Ó Broin said public housing is the answer and Sinn Féin has the vision and the plan to fix the housing system.
He said everyone should access to affordable accommodation.
Meanwhile, Sinn Féin's Pearse Doherty has made a blistering attack on the insurance industry, accusing it of "widely exaggerating" the number of fraudulent claims.
The Donegal TD and finance spokesman said the insurance industry "can't be trusted" and his party would "expose their lies".
Mr Doherty zoned in on the practice of dual pricing, describing it as a scandal and a "vicious attack" on the public involving "artificially high premiums".
He said he had submitted a 130-page document on a practice he claimed was "widespread" and welcomed an investigation that was now under way.
He told delegates: "We want this practice banned once and for all" and claimed only Sinn Féin in Government would deliver.
Additional Reporting Paul Cunningham