A total of 23% of wholesalers have sold cables not approved by the British Approvals Service for Cables in the past 12 months.

The statistics are revealed in a BASEC survey. Price followed by quality are still the key factors for customers when it comes to purchasing cables. BASEC approval is believed by wholesalers to be the third most important factor.

However, 30% said their customers are still inclined to buy a cheaper alternative.

The survey was carried out by an independent research firm.

Problems arising from the sale of non-approved cable included low conductivity, poor plastic insulation, damaged cable and delivery problems.

The survey comes at a time of increasing concern at the volume of faulty cables being sold in the UK, the majority of which have been imported from overseas.

BASEC chief executive Dr Jeremy Hodge said: “For wholesalers, if faulty or non-compliant products are discovered, they have to send them back to the manufacturer.

“For the manufacturer, it can be the loss of a good customer.

“For installers, too, it can prove to be expensive. They need to decide whether to strip out all the faulty cable or seek other options.

“Our message is clear: buy approved cable in the first place and you can save yourself a lot of time and money.”

BASEC ensures that cable products meet national, European and international standards through examination of production processes and controls.

It also carries out rigorous tests on products.