DIY giants Wickes are in hot water after an investigation revealed it cancelled out a 50% discount offer on a new kitchen by doubling prices the same day.

Consumer watchdog Which? has slammed the firm for its "misleading tricks" when advertising the Heritage Bone showroom kitchen.

On its website in August and September, Wickes advertised the kitchen at starting price £2,086, including a multi-buy discount of 50% off for customer who bought five or more units and 50% installation.

Which? objected that Wickes, which has stores across Suffolk including Ipswich, Stowmarket and Martlesham, had raised the list price of its kitchen before or around the time of the sale - meaning the sale price was the same as it had been before the increase.

It also complained the multi-buy offer could have made put pressure on customers to buy as they feared it would soon end, even though the price had been running for a long time.

The Advertising Standards Authority (ASA) upheld six complaints, including those from Which? that the promotion misled customers.

Trading Standards rules state retailers must have previously sold a significant number of units at a certain price to be able to legitimately reference the original price.

Wickes argued that the 50% discount was a multi-buy offer, comparing the cost of buying five units with that of buying fewer than five, and was not intended as a discount against a previous selling price.

However, data from Wickes showed it had made very few sales of four or fewer units, either before or after the multi-buy offer was introduced.

Wickes said multi-buy offers were a common and legitimate sales mechanism and were well understood by consumers, and added that its offer in relation to kitchen units was in line with market practice.

The ASA noted that Wickes had significantly increased the price of individual units on the day of the promotion, in one example raising the cost of a unit from £159 to £318, "effectively cancelling out any saving".

Similar price increases occurred on every unit across each range.

The ASA banned the advertisement and told Wickes not to alter list prices in a way that gave the misleading impression that a genuine saving could be made when that was not the case.

It also told the retailer not to base price claims on the cost of an individual unit where the ad was clearly promoting full kitchens.

Natalie Hitchins, Which? head of home products and services, said: "Our investigation exposed how a number of major kitchen and bathroom retailers were using potentially misleading tricks to make a sale.

"Today's ruling indicates that this offer from Wickes should never have been run in the first place.

"If it, and other retailers, continue to play fast and loose with the rules, we urge Trading Standards and the ASA to intervene and send a clear message that these practices have to stop."

Wickes declined to comment.