I assume the Deputy has in mind the application of a 1 per cent levy to all welfare benefits including child benefit. On the basis that the estimated provision for Social Welfare Benefits in 2012 is approximately €19.9 billion, which includes certain non-departmental operational costs but excludes administration and other administration expenses, the full year yield from the imposition of a 1% levy would be €199 million. This assumes that no new tax threshold, exemption, allowance or personal reliefs would be introduced to offset some of the tax.
The Deputy will no doubt be aware that many social welfare payments are already liable to income tax.