The Treasury has closed two "highly abusive" tax loopholes after a leading bank - believed to be Barclays - tried to avoid paying more than £500m.
The move is the first time the current government has clawed back taxes which have been avoided in the past and will ensure billions of pounds of tax are paid in the future.
Although the Treasury has not named the bank, the schemes have been widely linked to Barclays, which will cause the bank embarrassment because it has signed up to a code of practice against tax avoidance and has stressed the importance of good citizenship.