Virgin Media has apologised after customers reported spikes in latency between 7pm and 11pm.
Speaking to ISPreview.co.uk, a spokesperson said less than one per cent of Virgin Media customers may have noticed a deviation in their expected connection performance when using some tools and websites.
This, it said, has been caused by a link failure that caused Virgin Media's broadband capacity to drop by around 0.98 per cent.
Virgin Media stated that this will affect customers at peak times, but stressed it is working hard to restore the capacity as soon as it can.
"We apologise to the small number of customers affected for any inconvenience," the spokesperson added.
Those affected took to Virgin Media's community forum to air their complaints, with one person describing the service as "unusable for anything more than email or web".