The government has been accused of a "party political stunt" for pressing ahead with a review into industrial relations.
The review will be led by QC Bruce Carr and will look into allegations of "extreme tactics" during disputes.
The move was announced last year by the Prime Minister following a dispute at the Grangemouth refinery in Scotland.
But unions will not be involved in the review, which they said had a narrower remit than originally planned.
TUC general secretary Frances O'Grady said: "This review may have been announced with great fanfare by the Prime Minister, but the delay in setting it up, the limited terms of reference and the exclusion of the promised consideration of employer behaviour, such as blacklisting, confirms that it was never anything more than a headline grabbing party-political stunt."
Cabinet Office Minister Francis Maude said: "This Government's long-term economic plan is building a stronger, more competitive economy to secure a better future for Britain.
"Trade unions can play a constructive role in the modern workplace, but allegations of union industrial intimidation tactics - which include attempts to sabotage business supply chains - are very serious and may be damaging our economy's competitiveness, which would make our future less secure.
"That's why it's right to have this review to get to the bottom of these tactics and to determine whether the existing law is effective."
The government said it wants to assess whether or not the current legislation dealing with activities taking place during industrial disputes is fit for the 21st century.
The review will include the alleged use of extreme tactics in industrial disputes, including so-called "leverage" tactics and the effectiveness of the existing legal framework to prevent "inappropriate or intimidatory actions" in trade disputes.
The review will make proposals and recommendations for change.
Mark Serwotka, leader of the Public and Commercial Services union said: "This is far from an independent review, it's a political stunt to try to undermine trade unions and our ability to campaign against rogue employers.
"Carr is one of the bosses' QCs of choice who has carved out a career arguing against workers' rights."
A Unite spokesman said: "This is a cynical Tory attempt to divert attention from the cost-of-living crisis and the gross inequalities they have created - something strong trade unionism is needed to redress.
"The government is also worried because Unite is starting to use leverage campaign techniques to halt the sell-off of hospitals and other NHS facilities, and exposing the sleazy links between Tory MPs and private health care companies.
"Unite will shortly step up this campaign regardless, in order to save our NHS.
"The inquiry is to be headed by a lawyer with anti-union form going back years - Carr has publicly argued in favour of draconian laws against unions. No-one can place any trust in his objectivity. His only role is to rubber-stamp George Osborne's campaign messages."