Disability charities are threatening to challenge the government's Budget in the courts on the grounds that the Treasury had not considered its impact on disabled people.
The Disability Alliance and the Disability Law Service are to seek a judicial review of the proposals.
Under the Equality Act 2010, public bodies are legally obliged to give due consideration to their duty to promote disability equality when carrying out their functions.
However, on BBC Radio 4's Today programme yesterday, Treasury minister Mark Hoban refused five times to confirm that the government had undertaken an impact assessment of the Budget's effect on disabled people.
Vanessa Stanislas, the Disability Alliance's chief executive, said: "Disabled people and other disadvantaged groups require greater support from government services and benefits.
"To hear that the government announced the Budget without considering whether disabled people will be disproportionately affected by cuts to public spending and benefit reform is deeply alarming."
The Budget is already facing a legal challenge from women's equality charity, the Fawcett Society, which has accused the Treasury of failing to consider its disproportionate impact on women.
A Treasury spokesperson said: "Departments consider the impact of the Budget measures on gender, race and disability as they develop and implement the policies. This is in line with their legal obligations."
Yesterday, the Institute of Fiscal Studies branded the budget "regressive" and social care experts said it would put a strain on services.
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