The second stage of the Welfare Reform Bill was passed in a late-night vote in the face of strong opposition from Sinn Féin and the SDLP.
The most radical overhaul to the welfare system in Northern Ireland in years was debated at Stormont on Tuesday, as politicians remained in discussions until after midnight.
Key features of the new bill include a universal credit to cover a range of benefits, a personal independence payment reassessed every three years to replace Disability Living Allowance, and housing benefit reforms.
Sinn Féin wanted to defer it and tabled an amendment to halt the region's Welfare Bill in its present form.
However, the DUP believe a failure to adopt the reforms could see the Executive lose out on over £200m of Treasury funding - and the party insists there is simply no time for deferral.
In the lead up to a decision, SDLP leader Alasdair McDonnell said that Sinn Féin's call to delay the legislation had come too late and that the party should have entered a petition for concern.
"The maximum point of pressure on Whitehall would have been not to defer the Welfare Bill but to derail the Bill," he said.
But Alex Maskey, Sinn Féin social development spokesperson said Mr McDonnell's comments were "laughable nonsense" and said the SDLP had not brought any proposals forward regarding the welfare reform.
At the beginning of a marathon debate, Minister McCausland said that the House had a "clear choice".
If there are substantial costs involved in changes we want to make to this Bill, we will have to pay for them.
Nelson McCausland, DUP
"As Minister for Social Development, I would urge in the strongest possible terms that such an approach would be dangerous to our economic position, hugely damaging to our public services, and indefensible in terms of the possible consequences for those people who are struggling to work and support their families with little or no support from the public purse.
"Breaking parity is a choice we can make, but it will have huge costs. Those costs will be met through less money for schools, less money for hospitals, less money for the police, or else we will have to find the additional resources from introducing local charges to meet the costs."
Sinn Féin said the reforms are flawed and are targeted at the most vulnerable and disadvantaged people in society.
They want the deferral to go ahead so that further negotiations take place between local politicians and the coalition Government in London.
Mickey Brady, proposing the amendment, said: "At the outset, I would state that tabling a reasoned amendment is not about defeating the Bill.
"A reasoned amendment is about creating an opportunity for further consideration and adjustment; it's not about curtailing the legislative process, but using the legislative process to promote better outcomes.
"Every political party in this Assembly has expressed serious concerns about this legislation and that includes the DSD minister and his party, and indeed members of his own party voted against this Bill in Westminster."
The draft legislation proposes a bedroom tax could be applied to social housing tenants who occupy more bedrooms than they need, in an attempt to encourage them to move to smaller properties.
But the Federation of Northern Ireland Housing Associations claims some tenants could be left paying shortfalls of up to quarter of their rent.
Remember this - the British government told us that we are due to some flexibility because our circumstances are worse. Let us honour that and deal with it.
Alex Maskey, SF
Cameron Watt, chief executive of the Federation, said: "We have great fears that the bedroom tax is going to hugely hurt social tenants in Northern Ireland.
"Social tenants in Northern Ireland will be disproportionately affected by this policy because, in Northern Ireland, the majority of social housing stock is family-sized accommodation and there is a real shortage of one and two-bedroom social homes."
Cash for the housing associations currently comes from Westminster via the Department for Social Development, but the department is proposing withholding some of the cash - which Mr Watt said will have a knock-on effect on tenants.
He continued: "It will also cause major problems for landlords (like the Housing Executive and housing associations) who will face a big increase in arrears, affecting their ability to build new social housing."
The benefits shake-up hopes to help people back to work by gradually cutting benefits, so claimants do not lose out on cash by taking a low-paid job and losing their allowances.
The cost of welfare in Northern Ireland is £5.1 billion annually, expected to rise to £6.7 billion by 2019.
The Welfare Reform Bill will keep payments such as the winter fuel allowance and cold weather funds.
The Social Fund - which allows people in need to buy essential items through government grants and loans - is being abolished in GB and replaced by £30 million a year, ring fenced by the Executive, to prevent people from visiting loan sharks.