Tolley's Yellow Tax Handbook, the 'tax bible' used by all accountants, has more than doubled in length since the Labour Party came to power in 1997.

The Conservative party claimed this was proof of the huge number of tax rises, changes and other fiddling by Gordon Brown.

The latest edition of the Handbook, used by all accountants as their main reference book, is a whopping 9,806 pages.

It was just 4,555 pages when Gordon Brown took over as chancellor in 1997.

Theresa Villiers, shadow chief secretary to the Treasury, said of Brown: ‘He is making tax law more and more complex, forcing British managers to spend time wrestling with tax returns rather than working out how to compete in the new global economy.'