We take very seriously any action by suppliers which undermines consumer confidence

John Neilson, Ofgem

Unscrupulous sales techniques used by energy companies include forging signatures and falsely claiming that contracts were agreed over the telephone, Energywatch said.

"Energywatch demands that the energy companies clean up their act. Their cowboy tactics are widespread, on the increase, and can cause immense distress and annoyance to consumers," said Energywatch chair Ann Robinson.

Regulatory framework

Of the one million calls received by the watchdog last year, one in nine concerned high pressure sales.

Energywatch called on power regulator Ofgem to tighten up industry rules of conduct on sales, and urged it to start fining rogue power companies when it gains the power to impose financial penalties later this year.

Energywatch also called on the power providers to set up a database of addresses that are off-limits to sales staff.

A spokesman for the power industry said it did not condone mis-selling by its employees.

"We will not tolerate fraud against our customers nor our reputations being soiled in any way," said Philip Daubeney, chief executive of the Electricity Association.

Privatisation pressure

The rise in complaints over unscrupulous sales tactics reflects increased competition between rival providers in the UK's liberalised energy markets.

Ofgem said on Wednesday that one million consumers switch energy providers every month, with a total of 15 million changing to a different gas or electricity supplier in the last four years.

The regulator also pledged to crack down hard on cowboy salesmen.

"We take very seriously any action by suppliers which undermines consumer confidence," said John Neilson, Ofgem's managing director of customers and supply.

Earlier this month, a panel of MPs criticised Ofgem for failing to make it easier for consumers to change electricity providers.