ROGUE electricity salesmen are lying to get into homes in the borough and tricking residents into signing contracts, the MP for Twickenham has complained.

Dr Vincent Cable has launched a crusade against representatives from Southern Electric who he says have been preying on vulnerable or confused residents in Hampton.

The MP has warned residents not to let Southern Electricity salesmen into their homes after one of his own staff was a victim. He has also written to the firm's chief executive, threatening to raise the issue in Parliament.

Dr Cable's constituency caseworker answered her Percy Road door to two men wearing Southern Electric badges and uniforms. One told her there had been an error in billing energy supplies in her road and they were calling to check the meters.

They did so, then asked to see examples of her gas and electricity bills and appeared to check them against details on a clipboard. One of the visitors told her she was overpaying on her gas bill and claimed that Seeboard, her current supplier, were middle men' and that Southern Electric actually supply the gas in Hampton. She could, they said, save money by cutting out the middle man.

The woman, who deals with many cases of energy misselling on Dr Cable's behalf, knew this was utter rubbish'. The salesmen went on to try to prejudice her against Seeboard on the grounds that it is French-owned.

She threw them out of the house.

Dr Cable told the Times: "They chose the wrong person to try to intimidate in my rather formidable caseworker, but dozens of residents must have been exposed to these people. If anyone has been missold one of these contracts, contact me and I shall demand that the company apologise and withdraw it."

The watchdog Energywatch says it has received hundreds of complaints about Southern Electric's sales tactics and has called in the regulator, Ofgem.

Energywatch chairman Andrew Horsler said Southern Electric salesmen use a variety of lies, he said. "Some claim to work for Ofgem or Energywatch itself, others tell consumers they are on an out of date tariff, or their electricity is currently coming from abroad.

Some consumers reported that Southern Electric salesmen have become intimidating when their cover is blown, while other people signed apparently innocuous forms and were shocked to later find they had signed up to change energy suppliers."

However, Denis Kerby, spokesman for Southern Electric, said: "For every complaint we receive, we have 2,000 satisfied customers. That doesn't alter the fact that a complaint like this is a serious matter. We're horrified by any allegation of misselling. Our reputation is won or lost on things like this. It's important we are seen as a trustworthy company."

He said agency salesmen are used in the Hampton area instead of direct employees, but Southern Electric puts a lot of effort into its recruitment, training and monitoring to ensure salesmen behave ethically.

Mr Kerby said Dr Cable's complaint would be investigated fully and the salesmen in question would be taken off work for questioning.