Britain's tax system has become "ridiculously complex" according to the Liberal Democrats.

The party launched an internet-based campaign seeking ways of making tax regulations simpler and less of a burden on business.

"Britain's tax system is ridiculously complex and that complexity costs business, individuals and the government. At every Budget the level of complication increases and the tax maze gets longer, Treasury spokesman Edward Davey said.

"The current system is complicated and opaque and is a costly minefield to many individuals and businesses."

Davey also called on Gordon Brown to take action in Wednesday's Budget.

"Liberal Democrats believe Gordon Brown should announce a new strategy for simpler tax in tomorrow's budget," he said.

"It is no longer enough to have a 'comprehensive spending review' without a 'comprehensive taxation review' to assess its' impact on business."

He said the government should introduce a series of measures, including simpler marriage allowances for Britain's pensioners, a shorter annual tax returnand an easier VAT reclaim system for business start-ups.

The party is also beginning an internet-based search for new ideas through a specially designed website and a monthly e-newsletter, which it says will be sent to hundreds of top tax professionals, businesses, academics and finance journalists.

The website suggests the possible abolition of film tax relief, saying that only 13 per cent of the productions given permission to use the relief last year were movies.

Through the electronic newsletter and linked web articles, the Liberal Democrats pledge to consult every month on a range of modest and radical reforms aimed at minimising tax compliance costs.

The Lib Dems say they will consult on replacing the annual Finance Bill with a biennial bill, abolishing the contributory principle of national insurance and merging Customs and Excise with the Inland Revenue.