Simplifying the benefits system will help 300,000 families into work, Deputy Prime Minister Nick Clegg has said.
Government proposals to consolidate existing benefits into a single out-of-work and in-work payment will be unveiled in a white paper on Thursday.
Writing in the Guardian, Mr Clegg said the universal credit plan would remove "artificial disincentives" to work.
Labour has indicated it will support reforms to simplify benefits while opposing "reckless" cuts to welfare.
The party failed in an attempt to force ministers to rethink changes to housing benefit - which critics say will force thousands of people out of their homes - after losing a Commons vote on Tuesday.
This was despite concerns being expressed by a number of Lib Dem MPs about plans for a weekly cap on payments and a 10% cut in benefit to those on jobseeker's allowance for more than a year.
Details of the universal credit plan - a flagship initiative of the Work and Pensions Secretary Iain Duncan Smith - will be unveiled on Thursday.
Ministers say it will make work pay by ensuring people keep more of their income when getting a job and having benefits withdrawn more gradually than at the moment.
Mr Duncan Smith won a battle with the Treasury over funding the upfront costs of the reform - which are estimated to run into the billions - but critics have said the changes will not have any effect until the end of this Parliament at the earliest.
Writing in the Guardian, Mr Clegg - who will stand in for David Cameron at prime minister's questions on Wednesday - said the plan "should reduce the number of workless households by 300,000 within three years of implementation".
"Our reforms will effectively remove the artificial disincentives created by existing rules about the number of hours people have to work," he wrote.
"It must be worth working even for a few hours a week."
Shadow work and pensions secretary Douglas Alexander said Labour would work with the government on welfare reform where it agreed with their approach.
"We're interested in the proposal for a universal credit and I've said, in principle, of course I support a simpler benefits system and making it easier for people to make the transition from benefits and into work," he told the BBC on Tuesday.