National Lottery website and app are both down ahead of tonight's Lotto draw.
Customers are unable to access the site to purchase tickets or check results following a power failure.
The National Lottery responded to a user's question on Twitter saying: "Due to a power failure in the Watford area this morning, some of our services have been affected - including our website and Contact Centre.
"We're working to get services back up and running as quickly as possible and are really sorry for any inconvenience caused."
Those trying to use the website or app are being hit with a 'temporarily unavailable' message.
According to Down Detector, the independent outage monitor, problems were first raised at around 8am this morning which have continued throughout the day.
At its peak, around 565 people complained about the problems every minute.
Some customers are getting frustrated after recieving email's to say they had won in last night's EuroMillions draw but due to the outage, they cannot check their winnings.
"Overnight email from #NationalLottery saying I’ve won something. However their website is down. The tension is mounting," tweeted one.
Another said: "How bloody annoying is this @NationalLottery ? HOW MUCH HAVE I WON."
"So the national lottery app and website is down. i just wanna check if i’m a millionaire or if i have to work today," added a third.
Tonight's Lotto draw is still expected to go ahead as usual.
