After a committee of MPs said the bedroom tax unfairly affects disabled people, Tim Farron says his party will push for change.
The firm that carries out assessments for disability claimants is quitting its contract early, the Government has announced.
MPs have voted in favour of the government's plans to cap welfare spending - her is how it will work.
Work and Pensions Secretary Iain Duncan Smith will credit Chancellor George Osborne for helping to create 1.7 million jobs since the election but will add that welfare reforms have also played a part in the current level of employment.
– Work and Pensions Secretary Iain Duncan Smith
Whilst others have questioned and puzzled over the record employment Britain is now seeing, as the Work and Pensions Secretary I have long believed that the strength of our labour market would both drive Britain's great economic recovery, and increase as a result.
First, this Government created the conditions for growth, and gave businesses the freedom and confidence to create jobs.
Second, we drove a programme of welfare reform where every change was designed to get Britain back to work - giving people previously left to languish out of work the skills and the incentive to take those jobs.
Work and Pensions Secretary Iain Duncan Smith will claim that the Government's package of welfare reforms have helped "get Britain back to work".
Mr Duncan Smith will say in a speech in London that the strength of the labour market is evidence that benefit reforms are also having an impact by boosting economic activity.
He will also accuse the former Labour government of trapping people in welfare dependency and robbing them of the drive to go to work, while claiming his reforms have given jobless people the incentive to seek and take employment.
Mr Duncan Smith will say that changes to benefits have played a crucial part in "creating a stable economy matched by a strong society where people are ready and capable of work".
A raft of welfare reforms have been implemented in the last year, including the so-called "bedroom tax", the introduction of Personal Independence Payments for disabled people and the imposition of the £500-a-week benefit cap.
New parents will be left £224 out of pocket by 2015 thanks to below-inflation rises to child-friendly benefits, a children's charity chief has said.
Belinda Phipps, chief executive of the National Childbirth Trust, explained:
– Belinda Phipps,
We strongly support this call for family-friendly benefits to increase in line with prices. This reinforces NCT research, published last month, showing that below-inflation increases to maternity and paternity pay mean new parents will lose out by £224 by 2015.
These changes will hit families' finances hard at a time when they should be focusing on bonding with their new baby.
We call on the Government to show that they value parents by increasing maternity and paternity pay in line with prices.
Real terms cuts to maternity pay and child benefit have left expecting parents hundreds of pounds worse off, the TUC has claimed.
The planned 1% increase to statutory maternity and paternity pay, adoption pay and child benefit introduced was still a cut, the TUC argued, because it was below the rate of inflation.
This was the fourth successive cut in the value of the benefits, which it claimed had led to new and expectant parents being £450 a year worse off, the union added.
General secretary Frances O'Grady said: "New babies are wonderful - but they can also be expensive, as any parent can attest. That's why it's important we protect the real value of family friendly benefits to give new parents the help they need to buy baby essentials.
"Family friendly benefits have come under stealth attack in every Budget since mid-2010. Successive years of real-terms cuts will leave expectant and new parents up to £450 worse off this year - enough to buy a year's supply of nappies, wipes and babygrows."
The Liberal Democrats wants to see the so-called 'bedroom tax' changed so that people do not face moving out of their home with nowhere to go, the party's president has told ITV News.
Current policy means social housing tenants who have a spare room face having their housing benefit reduced.
Speaking to Deputy Political Editor Chris Ship, Tim Farron said Nick Clegg shared "the view that this is something that we want to see changed".
Citizens Advice has said an extra room "can be a lifeline" for a disabled person, calling it "as vital as a guide dog or a wheelchair".
Chief executive Gillian Guy said for many people a spare room "is essential to their wellbeing" as it is needed for dialysis equipment or room for a carer.
Ms Guy said: "Many sick and disabled people have bedrooms which have been adapted to help them to cope with their condition.
"Moving disabled people out of their houses is not only a potential risk to their health, but can cost the individuals affected and councils significant amounts of money if they need to start from scratch in a new home."
The head of homeless charity Crisis has said the Government risks forcing poor people out of their homes because of changes to housing benefit such as the 'Bedroom Tax'.
– Leslie Morphy, Chief Executive of Crisis
"The Government must listen to this verdict from MPs across the political spectrum and rethink its cuts to Housing Benefit, particularly for those who cannot change their circumstances by working or who are struggling in low paid jobs. Without prompt action, the Government risks driving homelessness still higher."
Shadow work and pensions secretary Rachel Reeves said it was "completely unfair" that many disabled people were hit by the "bedroom tax" and charged for the space used to store essential medical equipment.
"Britain can't afford another year of David Cameron and Nick Clegg's tax on bedrooms," Ms Reeves said.
"If they won't listen to the country and scrap their hated bedroom tax, then a Labour government will," she added.
The chair of the Work and Pensions Select Committee has said those being hit by the withdrawal of the spare room subsidy are often not those the policy was intended for.
Dame Anne Begg said: "Many of the people being hit by the so-called 'bedroom tax' are in vulnerable groups, very often people with disabilities who can't move house."