Virgin Media has announced plans to introduce gigabit broadband to almost 15 million households by the end of 2021.
The internet service provider has said more than a million people will be able to access the "hyperfast" speeds this year, starting with Southampton, where it has been trialling the technology.
It will also bring gigabit broadband to one other city yet to be decided in 2019, before rolling out across its entire network over the next two years.
Speeds of one gigabit per second (1Gbps) would be around double what Virgin Media currently offers from its fastest product, which it claims has an average download speed of 516Mbps (megabit per second).
Upgrades are being made to the company's existing core cabled network and will require a new router, chief operating officer Jeff Dodds explained.
"We have a cable network across the UK that we have invested in and kept in extraordinarily good shape over the years, so we're able to make these changes relatively quickly and relatively inexpensively," he said.
The move comes in anticipation of greater demand for quicker broadband, with streamed ultra high definition 4K content expected to increase and the arrival of cloud gaming likely to be an added strain on providers.
"If all homes are streaming their content in 4K as standard today that would increase capacity requirements by about 12 times," Mr Dodds continued.
"And if they were to do that not in 4K but in 8K, you can only imagine the increase in bandwidth requirements."
According to Virgin Media, its gigabit service is around 20 times faster than the UK average broadband connection.
This would mean downloading an ultra high definition 4K film of about 20GB in size taking less than three minutes, compared to nearly an hour (52 minutes) on the UK's average connection, it claims.
Mr Dodds said that the Liberty Global-owned firm was not ready to share pricing details, though it will be a "premium service".
"We welcome Virgin Media's commitment to investing further in its network, providing gigabit speeds to millions more households," said Sharon White, chief executive of Ofcom.
"This shows the race to roll out ultrafast speeds to people and businesses across the UK is really gathering pace."
Paolo Pescatore, an analyst from PP Foresight, described the development as a "great move for UK plc".
"Competition is heating up with Openreach accelerating its own efforts to match the alternative network providers like CityFibre and the many others emerging from out of the blue," he said.
"Arguably, this move should have come sooner but will bring about plentiful benefits to Virgin Media customers for potentially a few quid more."
