A controversial Government scheme to allow workers to swap shares for employment rights has been attacked by union leaders as an "expensive gimmick".
The TUC said the scheme, which takes effect from today, will strip workers of basic employment rights and could end up costing the taxpayer £1 billion.
The employee ownership scheme, announced by Chancellor George Osborne at last year's Conservative Party conference, allows workers to trade employment rights for shares in a company.
Unions have warned the move would make it easier for workers to be sacked, and could be used as a tax loophole by companies.
TUC general secretary Frances O'Grady said: "The Chancellor's shares for rights gimmick may have cheered delegates at the Conservative Party conference but it could end up costing taxpayers hundreds of millions of pounds.
"At best the scheme will be completely ignored and consigned to Parliament's pointless policies 'hall of shame'.
"But it could turn into a gaping new £1 billion tax loophole, allowing the super rich to dodge paying tax on company shares. At a time when the public finances are under strain, the Government should be closing these loopholes, not creating new ones.
"Ordinary workers who may be forced to become employee owners in order to find work could end up giving up basic rights such as redundancy pay for worthless company shares."