A committee of MPs has criticized the UK Treasury's conclusion to increase a levy on the oil and gas industry calling it an "opportunistic raid".
The Energy and Climate Change Select Committee report said the way in which the £2bn hike was announced may have undermined investor confidence.
The MPs suggested the UK government should now attempt to do more to restore industry confidence.
The SNP's Mike Weir said the committee was correct to criticize the move.
The report said: "If the government is serious about maximizing production from the UK Continental Shelf (UKCS), it needs to consider the long-term impact of changes to the tax regime on investment.
"The evidence on the impact of 2006 increase in the supplementary tax charge on oil and gas production in the North Sea is inconclusive, but there is a clear need to sustain investor confidence by avoiding surprises, such as the further increase announced in the 2011 Budget.