Direct action group UK Uncut will join members of disability campaign groups in occupying an area of central London on Saturday.
The groups said they wanted to voice their anger at the impact of the Welfare Reform Bill, warning that hundreds of thousands of families will lose their homes or become "imprisoned" inside.
UK Uncut attacked the argument that savings were needed to help tackle the deficit, saying that far greater amounts of money were lost through tax-dodging.
Sarah Evans of UK Uncut said: "British people are proud of the welfare state because it has provided for the 99% for over 60 years. This Bill will remove vital lifelines and force people into deeper poverty, making many prisoners in their own homes.
"There are alternatives: we can afford a fair welfare system that provides for all. Instead of taking serious action against rich companies' tax-dodging and their fancy corporate lawyers, David Cameron is instead choosing to make the poorest and most isolated pay for the economic crisis they didn't cause.
"At least £25 billion of tax is avoided every single year by super-rich companies and individuals, far more than the Government hopes to save through this devastating Bill. The Welfare Reform Bill is cruel and unnecessary and it must be stopped."