British Gas workers have voted massively in favour of strikes over claims of "macho management" at the company, raising the threat of walkouts by engineers and other employees, it was announced today.
The GMB said its members backed strikes by 82%, and industrial action short of a strike by 90% in a high turnout of the 8,000 workers balloted.
The union has given British Gas a week to respond before deciding its next move.
General secretary Paul Kenny said: "The vote clearly vindicates what we have been telling the company. It is now time for them to sit up and take notice.
"We are giving British Gas a week to give us a constructive response. We want an independent inquiry into the profit at all costs culture at British Gas.
"We will met with shop stewards to determine what form of action should be taken should British Gas fail to lift the conflicting demands on its workforce."
The GMB said British Gas had turned from being a reasonable employer where people had job satisfaction into one with a culture of bullying, customer exploitation and profits at all costs following recent management changes.
Matthew Bateman, director of heating services at British Gas, said: "We are not surprised by this ballot result, given the GMB's recent false accusations and reckless scaremongering.
"The GMB has still not told us the grounds for this dispute, even though we have asked for this information several times.
"We are, of course, disappointed by the GMB's action - especially as our engineers, who have worked so hard over winter, recently voted British Gas one of the top 25 big companies to work for in the Sunday Times survey for the second year running.
"We have robust contingency plans in place to make sure our service to customers is unaffected, and we remain committed to talking with the GMB and avoiding this unnecessary industrial action."
Conservative Party chairman Eric Pickles said: "We are facing a spring of discontent as yet another union flex their muscles and threaten to walk out.
"We need a strong government to stand up for the interests of this country, not one that's reliant on union barons propping them up.
"If the Prime Minister has any grain of moral authority left, he will show some backbone and condemn this walkout."