Virgin Media’s broadband service went offline for tens of thousands of users in the run-up to peak time.
The Downdetector service recorded more than 40,000 reports at 5.20pm, which coincided with the government’s daily coronavirus briefing.
Reports of an outage then began to fall before rising to more than 42,000 at 7.20pm.
Virgin Media said its peak time is between 8pm and 10pm.
Downdetector’s data suggests there were 1,577 reports of outages at 8.30pm.
By 9.30pm, a live map on the website showed that most outages were in the south of the country.
A Virgin Media spokesperson said: “We’re currently investigating an intermittent broadband issue that started earlier this evening. The issue is causing broadband connectivity to drop for a few minutes before returning again.
“We know that this is not being caused by increased usage or a lack of capacity but is due to a network technical fault.
“Our teams are urgently looking into the problem and working flat out to fix it. We know how frustrating this is for customers and apologise for any inconvenience caused.”
One affected user tweeted the company, writing: “It’s a big inconvenience trying to work from home, please fix it before tomorrow.”