A crackdown on misleading broadband adverts will ensure at least 50pc of customers can receive advertised speeds, drastically reducing providers' fast internet claims.
It comes after Ministers, consumer bodies and members of the public complained that current rules, which let firms advertise speeds received by the top 10pc of customers, were misleading.
The move is also a victory for this newspaper's Better Broadband campaign which has repeatedly highlighted that consumers are suffering as a result of lower than advertised speeds in their homes.
The new rules are set to force firms to reduce advertised speeds by as much as 25pc.
In one examle provided by Ofcom, the telecoms regulator, Plusnet's "up to" 76Mbit/s fibre broadband package is around 25pc slower for the average customer, who received a speed of 56.4 Mbit/s.
Which? has warned current rules allow brands to advertise attractive high speeds which are misleading an estimated 84pc of consumers who are not aware of it.
Digital Minister Matt Hancock said: "So-called 'up to' speeds that only need to be available to 10pc of consumers are incredibly misleading, customers need clear, concise and accurate information in order to make an informed choice. "In the past, too many people haven't been getting the speeds they thought they signed up for, and I'm pleased this is being put right."
Today the Committees of Advertising Practice (CAP) has launched a consultation on toughening up the standards following research which found they are currently likely to mislead consumers. The study, commissioned by the Advertising Standards Authority (ASA), found most consumers think they are likely to receive a speed at or close to a provider's headline claim when, for many, that is not likely to be the case.
Previous independent testing by consumer groups has found up to three-quarters of households are paying for advertised broadband speeds they have never received.
As well as the proposed 50% requirement, CAP will also consult on whether consumers would like the headline speed to be presented as a range of speeds or an average speed, and if it should available at peak times or over 24 hours.
Each ad will also have to urge potential customers to check with the provider about the speed they are likely to receive.
An Ofcom spokesperson: "Ofcom is concerned about the gap between advertised broadband speeds and what people actually receive.
“We support the CAP’s ongoing work to provide greater clarity and accuracy in broadband advertising, so that customers can shop around with confidence.”
Till Sommer, policy lead at the Internet Services Providers' Association, which represents broadband providers, said: "The consultation marks a welcome shift to the current standards for broadband speed advertising which ISPA feels no longer deliver for consumers and our members.
"We particularly support CAP’s suggestions that adverts should prompt consumers to ask providers for a more personalised speed estimate."