BT has announced the locations where broadband subscribers will be able to access the web at up to 40mbps over fibre networks from "early 2010".
BT is already behind the likes of Virgin Media when it comes to faster fibre broadband access, as Virgin is already selling a 50mbps access package to some customers across its cable areas.
Most BT broadband customers are currently offered only an "up to" 8mbps service over traditional copper access networks.
BT says its local access broadband division Openreach will deploy fibre to the cabinet (FTTC) technology at 29 exchanges across the UK.
This will bring speeds of "up to" 40mbps and "potentially 60mbps" within reach of 500,000 homes and businesses, said BT.
Areas of Belfast, Cardiff, Edinburgh, Glasgow, London and Greater Manchester will be among the first locations to benefit from an initial deployment of the technology.
Although the majority of the locations are urban, two of them - Calder Valley (near Halifax) and Taffs Well (near Cardiff) - are not, and BT says it will be looking to learn lessons from deploying fibre in rural and less crowded area.
BT says the next set of faster fibre locations - serving a further one million homes and businesses - will be announced this autumn.
Although Openreach will deploy the technology, it will be up to communications providers (CPs) to develop services based on that technology and to sell them to customers. Those communications providers include BT divisions and their rivals.
BT has pledged to spend £1.5bn by 2012 to ensure that 40% of UK homes and businesses - around 10 million premises - can access fibre-based broadband services.
Steve Robertson, CEO of Openreach, said, "We have worked very closely with industry and with local and regional authorities to choose these sites, and I would like to thank everyone who has worked with us to make this happen. We are in discussions with many other authorities, so expect many similar announcements in the months to come."
Openreach will deliver fibre to the cabinet (FTTC) services by installing fibre between local exchanges and the street cabinets that sit between those exchanges and the premises served by them.
The fibre will increase the speeds available even though the last link in the chain - from the street cabinet to the customer premises - will remain copper.
Ebbsfleet in Kent already has access to fibre to the premises (FTTP) technology supplied by Openreach. Some customers there can get access speeds of up to 100mbps.: