Experts have calculated the reforms proposed in the pre-Budget report will cost the Exchequer Pounds 2bn instead of the Pounds 10-40m estimated by the Treasury.
Advisers have told the select committee the changes will inadvertently encourage people to reclassify income as capital gains.
Liberal Democrat committee member David Laws will challenge Brown to defend his proposals.
Speaking before the hearing Law said: ‘This is another major loophole which will allow well advised wealthier individuals to cut back their income tax liability.
‘This is yet another example of the chancellor’s meddlesome tinkeringapproach to tax policy badly backfiring.’
Does Darwin's theory apply to taxation? Colin ponders...
The UK tax gap fell in 2014-15 to its lowest-ever level of 6.5%, revealed official statistics published today
Changes to the tax system is urged to support the growth of entrepreneurs, found a report from the Grant Thornton UK, the Institute of Directors, and the Prelude Group
The EC has been instructed to draft a European Union (EU) directive authorising an EU financial transaction tax, which would apply to ten of the EU’s 28 member states