Every political leader should feel deeply ashamed that families have been "so badly let down" over the cost of living crisis, Colum Eastwood has said.
The SDLP leader said financial pressures facing households have become an "emergency" but politics in Northern Ireland "has failed people again".
He hit out the DUP and Sinn Féin, saying that for 15 years the two parties have had a "joint record of either bad government or no government".
Read more: Colum Eastwood: SDLP fighting DUP for final seat in key election battlegrounds
Speaking at the SDLP conference at Bellaghy, Co Derry, he said his party's "brilliant" candidates in the forthcoming Assembly election "offer everyone a new choice".
Mr Eastwood said tackling the cost of living crisis should be a priority and warned that "hot tempers at Stormont don't heat a single home".
"But the truth is, our politics hasn't responded, it hasn't acted and it has failed people again," he said.
"And I for one am deeply ashamed. Because it should shame every political leader that families have been so badly let down."
He criticised the DUP for refusing to re-nominate a First Minister so that £300million of unspent funds can be allocated by the Stormont Executive.
He claimed the DUP "only care about their own selfish needs" and collapsed the power-sharing Executive in February as a "desperation tactic - nothing more".
The Foyle MP praised his constituency colleague Mark H Durkan's attempts to "unlock" the funding through proposed emergency Assembly legislation.
He said his party would seek to "find a way in Westminster" to enable Stormont ministers to distribute the money and urged Secretary of State Brandon Lewis to intervene.
Mr Eastwood also hit out at the DUP's handling of Brexit and its response to Irish Sea trade arrangements under the Northern Ireland Protocol.
The SDLP leader said the DUP "forced through a hard Brexit" and "after getting the Brexit they said they wanted, they can’t deal with the damage of their own actions".
"And let’s be very clear - their latest tantrum won't work either. As long as a hard Brexit is imposed, the Protocol is here to stay," he added.
Mr Eastwood also said Sinn Fein "can’t escape from their responsibility for the failures of the last 15 years".
He added: "The truth is that the DUP and Sinn Fein have a joint record for the last 15 years – and all it amounts to is a joint record of either bad government or no government."
Addressing party members at Seamus Heaney HomePlace, he said: "All of our brilliant candidates offer change and they offer everyone a new choice.
"Because the truth is our people deserve more than the two terrible choices they have been stuck with for 15 years."
Mr Eastwood praised healthcare staff and other key workers for their efforts during the Covid-19 pandemic.
He called on the next Executive to pledge a pay rise of at least 6% for nurses and carers to acknowledge their "immense struggle" over the past two years.
In an unusual move for a political conference, Mr Eastwood also reserved praise for a member of another party, describing the UUP's Robin Swann as an "exceptional" Health Minister.
The start of the conference was delayed for about an hour following a security alert at an event in North Belfast organised by the John and Pat Hume Foundation.
Irish government minister Simon Coveney had to be evacuated from the Houben Centre on Crumlin Road after a van was reportedly hijacked and driven to the venue.
Mr Eastwood condemned the security alert, branding it an "attack" on Mr Coveney, others in attendance and the memory of former SDLP leader John Hume and his wife Pat.
Closing his speech, Mr Eastwood urged members to go out and tell voters in May's election that "more SDLP MLAs means more for their community".
"Tell them that they have the choice of an SDLP team that will put them and their family first.
"That they can choose change by choosing this team.
"That they can choose politicians who will finally, finally put people first.
"Conference, let's go out and make sure that people choose the SDLP."
Earlier, SDLP deputy leader Nichola Mallon claimed the DUP "merely reacts to the loudest loyalist voice on social media".
Addressing the conference, she said: "The truth is for DUP voters, vote Jeffrey's party and you get Jamie Bryson politics."
Read more: Colum Eastwood: SDLP fighting DUP for final seat in key election battlegrounds
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