The Labour leader Ed Miliband has said the Government had shown "incompetence" over its plans to limit the tax relief on charitable donations.
During a visit to a job support service in Stratford, east London, Mr Miliband said it was "a hasty and ill-thought through measure which is affecting Britain's charities."
The government appears to have tied itself in knots over the row on charitable giving.
The row over the cap on a tax relief for charitable giving is the latest in a string of rows that have erupted since the budget.
Charities and philanthropists have warned that Government plans to change the way it taxes charitable donations will discourage giving