A consumer watchdog is warning people to be on their guard against salesmen offering to read their gas and electricity meters.

Energywatch has been inundated with complaints from consumers in the Bradford district who have been persuaded into allowing Southern Electric salesmen into their homes.

They claim the callers get a foot in the door by claiming to be probing residents' complaints about high utility bills.

Energywatch says that, once inside, they read the meter and ask the consumer to sign a form to confirm the meter has been read - but what they are actually signing is a contract with Southern Electric.

Craig Hughes, of Northdale Crescent, Bankfoot, only realised what was happening when he was asked to sign a contract after he had allowed a representative into his home.

The 38-year-old team leader, who works at St Luke's Hospital, said: "A man came to the door saying he had had complaints that people's bills in the street were too high and asked if he could come in to read the meter.

"If he had said he was selling something, I would have told him I was not interested but he said he was from an independent organisation. He never said he was from Southern Electric.

"He knew how much we were paying because he read the gas and electric meters. Then he offered to halve the bills. When I asked him how, he said all I needed to do was give him direct debit details. It was only when I looked at the form he was asking me to sign I saw that he was from Southern Electric.

"I was taken aback and felt a bit silly when I realised," said Mr Hughes.

Mr Hughes did not sign up and told his wife, who left the house to warn a neighbour, only to find the same representative was already in her neighbour's living room.

Energywatch North East director Carole Pitkeathley said: "This is appalling. Energywatch will not tolerate these totally-unethical sales tactics. Energywatch contacted Southern Electric about other cases days ago and yet, today, we find out from other consumers that these representatives working on behalf of Southern Electric are still operating in this disgraceful manner.

"Many of the consumers who have contacted Energywatch are elderly and have been very distressed about a stranger entering their home in this way. This is wholly unacceptable."

A Southern Electric spokesman condemned the salesmen involved and said the company was conducting a full investigation.

She added: "We employ some sales people directly and some through agencies and we work very closely with them to make sure they do not mislead customers. We see no benefit whatsoever in misleading customers. These people are rogue salesmen and if people have been flouting our regulations and will not change their ways, they will be sacked."