The Public and Commercial Services union, which represents Revenue staff, released a comprehensive report into the fiasco earlier this month. While it did not raise the subject of strike action, Ian Lawrence, deputy group secretary at the PCS, told Accountancy Age that if lessons were not learnt, it could not be ruled out. 'We will not be in a position to tolerate that behaviour again,' he said.

The PCS report was passed on to the National Audit Office for inclusion in its investigation into the same subject, which a spokesman for the NAO said would be published 'sometime in the autumn'. One of the PCS' main grievances was whether the tax credits were rushed through for political reasons. 'In terms of accountability we would like the NAO to firmly identify who was at fault,' Lawrence said. The PCS is demanding improved training for Revenue staff, better facilities and improved conditions at Revenue centres.