Ken Jackson, general secretary of the Amalgamated Engineering and Electrical Union (AEEU) said the watchdog's plans to ask National Power and PowerGen to sell some of their plants would cost jobs and would not cut electricity prices.
A spokesman for the AEEU, which claims to be the largest union at the two firms with a total 1,500 members, said the divestment could cost over a 1,000 jobs out of a combined workforce of more than 7,000.
He said that the union had evidence that sales of capacity in a number of industries in the past had led to redundancies
Mr Littlechild has said he would consider asking large generators to divest some of their plants and added that he did not rule out a referral to the Monopolies and Mergers Commission if they refused.
Mr Jackson said: "This latest attack by the regulator is in line with his malicious vendetta against" the two companies. He urged Mr Littlechild to "stop carping and concentrate on helping the companies".
In a separate development, the Government yesterday signalled a delay in the publication of its long-awaited energy review because of the complexity of issues. The review was due to be published this week, but is delayed at least one week.Reuse content