Work and Pensions Secretary Iain Duncan Smith won't take part in the planned Labour debate on the "bedroom tax" later today.
The welfare reform - which the government refers to as the "spare room subsidy" - is the subject of an Opposition Day debate in the House of Commons.
The Secretary of State in charge of the policy however will not be there to defend it.
The Shadow Work and Pensions Secretary Rachel Reeves is expecting to debate the issue with a more junior minister from the government department.
A number of protestors are planning to travel to Westminster ahead of the debate and Labour sources suggest the Work and Pensions Secretary is "running scared".
Labour is forcing a vote in the Commons on a motion calling on the government to repeal the controversial policy.
Rachel Reeves claims the welfare change hits 660,000 housing benefit claimants with an average loss in payments of £720 per year.
The Labour motion reads:
Update: The Department for Work and Pensions has told ITV News Mr Duncan Smith had written to Rachel Reeves to tell her he would not be at the debate as he is at the International Conference on Youth Employmenton the Prime Minister's behalf, along with 20 heads of state including Angela Merkel and Francois Hollande.