The new coalition government's emergency Budget announced in June has hit the poorest families hardest, a leading economic think tank says.

The Institute for Fiscal Studies (IFS) said the measures announced in the Budget were "regressive".

Its analysis suggests the poorest households are set to lose the most as a precentage of net income due to benefit cuts announced in the Budget.

The Treasury said it did not accept the "selective" findings of the IFS.

"It is selective, ignoring the pro-growth and employment effects of Budget measures - such as helping households move from benefits into work, and reductions in corporation tax."