Brown shut down six corporate tax avoidance schemes, introduced a targeted anti-avoidance rule for capital losses and shut down avoidance plans for stamp duty land tax. The chancellor also closed a planning scheme used to avoid tax charged to controlled foreign companies.

Yet the Treasury didn’t seem to be satisfied with the anti-avoidance windfall, and also used the PBR to announce that it was planning to strengthen its disclosure regime powers further.

In the PBR the government announced that it would publish a consultation document later this month on a ‘new power’ that would provide it with further investigative muscle.

The state is planning to obtain the new power so that it can ‘investigate a scheme where there are reasonable grounds to believe that a promoter has failed to comply with its statutory disclosure obligations’.

Francesca Lagerberg, tax partner at Grant Thornton, said that although the disclosure regime had successfully closed down a number of tax planning schemes, the taxman obviously felt that the regime was still missing certain schemes that it felt it should be picking up.

‘It would appear that some individuals have been taking strong legal advice that they do not need to disclose certain schemes under the disclosure regime, and the authorities are introducing tougher measures to catch these schemes,’ Lagerberg said.

Advisers believe the possible measures the government could implement include additional search and investigative powers, or new legislation targeted at specific areas of tax planning.

‘The government probably feels that it is still a few steps behind on tax avoidance when it wants to be one step ahead,’ Lagerberg said.