Carphone Warehouse has been forced to remove an advert after the Advertising Standards Authority (ASA) branded it misleading.

The ASA said the mobile phone specialist’s ad for its monthly 4G mobile tariff packages made claims that could not be substantiated.

The Carphone Warehouse advert hailed: “UK’s lowest price – we check so you don’t have to”. But the watchdog said the ad’s small print contradicted its claims and consumers were “likely to be misled”.

It argued the statement implied the products on offer were the cheapest anywhere in the UK, but found the offer to exclude “online retailers without a high street presence”.

The small print said the lowest price is based on “new connections on selected networks on 4G tariffs”, and applies to “published prices”.

The ASA was also unable to substantiate the latter part of the retailer’s claim – “We check so you don’t have to” – because it only applied to three competitors: O2, EE and Vodafone.

ASA said: “A price promise did not justify a lowest price claim in the absence of such monitoring.”

A spokesperson for Carphone Warehouse told the Daily Mail’s This is Money: “We are disappointed with the ASA’s decision because we are the only independent high street retailer able to compare thousands of tariffs across the biggest networks and our own network iD.

“We update all of our price checkers daily to ensure we offer our customers the perfect deal that’s right for them.

“And with our price promise, if they find a cheaper deal, we will match it and pay their first month’s bill.”