The DUP needs to "get back to work or get out of the way", SDLP leader Colum Eastwood has said.
Addressing his party conference, Mr Eastwood said the DUP has "run out of excuses" in blocking Stormont power-sharing over Brexit's Northern Ireland Protocol.
He said Sir Jeffrey Donaldson's party must "come to terms" with the significance of the "massive majority" at Westminster in favour of the Windsor Framework deal.
Read more: SDLP leader Colum Eastwood: Unionists are engaging with our forum on Irish unity
Mr Eastwood said people in Northern Ireland have been left without a government in the middle of a health service and cost-of-living crisis.
Speaking at St Columb's Hall in Derry, he added: "Jeffrey Donaldson and his party finally need to hear the message that the majority of people here have been roaring at them for the best part of a year.
"After this week, the message they need to hear is very, very simple. The DUP need to get back to work or get out of the way.
"They have run out of excuses, they have run out of road and the public ran out of patience with them a long, long time ago."
Mr Eastwood, who took to the stage to the song Dreams by The Cranberries, said the SDLP has set out an "ambitious agenda of reform" for the Northern Ireland Assembly.
He proposed equal titles of "first ministers", their co-nomination by weighted majority votes and ending the "abuse" of the petition of concern.
He also called for a new weighted majority vote for appointing a speaker, saying it was "time to remove the poisonous politics of veto from the beginning of every mandate".
But the Foyle MP said that while the case for reform is "self-evident", the mandate of last year's Assembly election "first has to be respected".
Mr Eastwood told party members that "sharing power isn't just about sharing out ministerial Skodas".
"It means taking decisions to transform this place and the lives of everyone who calls it home," he added.
The Foyle MP, who outlined ambitions for the party including tackling climate change, said the SDLP's first priority in a restored Assembly would be to address the "outrageous" cost of childcare.
He added: "The SDLP will work day and night to deliver 30 hours' free childcare per week for the parents of all children under the age of five.
"There will be no limit on our ambition to support working families."
Mr Eastwood also issued a "warning" to the British government
"Keep your hands off the principle of consent. It cannot be altered to buy off hardline unionism. We won't allow it," he said.
On European Union membership and Irish unity, Mr Eastwood said rejoining the EU "can only be done in a new Ireland".
He added: "The reunification of this island is motivated by an unshakable conviction that by every measurable outcome we can build a better health service, we can build a better education service, we can build a better economy."
However, he said integrating two health services "will be one of the most significant challenges our movement faces".
Mr Eastwood said his party's New Ireland Commission, set up to consider future constitutional arrangements on the island, has "shifted gear" in its public engagement and outreach to unionists.
He added: "We don't just preach about a future that accommodates the people of our island. We are putting in the hard yards to make it happen."
Mr Eastwood acknowledged the SDLP went through a "bruising" election last year in which the party lost four MLA seats, dropping from third-largest party at Stormont to fifth-largest.
He said polls and surveys "have not made for comfortable reading", but he insisted the SDLP is a party with a "new mission".
"We are a party that is ready to get back to work again and we will win again," he said.
Concluding his speech, he said: "Together we can build a movement for a new Ireland."
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