The DUP is more interested in facilitating Tory Brexit than protecting the livelihoods of people in Northern Ireland, Mary-Lou McDonald has claimed.
The Sinn Fein president called on the unionist party to commit to mutual recognition and rights.
The DUP has secured extra funding for Northern Ireland public services as part of its pact to support the Conservative minority Government in key Westminster votes including Brexit.
Stormont has not sat for months in a row between former coalition partners the DUP and Sinn Fein over the place of the Irish language and a host of other issues.
Mrs McDonald said: "Regrettably, the DUP remain in a fixed, negative space, more interested in facilitating the Tory Brexit than protecting the rights and livelihoods of people in the North.
"So, the two governments must act now to deliver on marriage equality, to address the legacy of the past and to deliver Acht na Gaeilge."
She repeated her call for the Irish and British governments to convene an intergovernmental conference on the way forward.
"Unionism cannot and will not hold back the tide of change and equality."
She said she wanted to lead the party into a progressive government in the Republic.
"I want to do that from a position of strength, a strength derived from the support of the people. After the next election, Sinn Fein will talk to all political parties and the independents."
The party would consider if it was possible to agree a programme for government on the basis of "shared prosperity", inclusion and accountability.
"To those who are on an agenda to exclude us, I invite them to wake up and smell the coffee.
"To realise that Irish political life is no longer dictated by them, it is no longer their way or the highway. We are here, we are equal."
She said Sinn Fein in Government would work to ensure no child was living in a hotel room.