Chariot, administrators of the new Monday lottery, have admitted that their Web operations were disrupted on its first day of draws by what they called an "unexpected level of interest".
The lottery, which has been promoted as a fairer alternative to the more established National Lottery, is run solely through www.playmonday.com. Its launch on Monday was plagued by technical problems and saw the registration deadline for the draw extended by four hours.
"At one stage there were up to 10,000 players trying to access the site at once, although the general rate for the day was in the region of 4,000 enquiries at any one time," a spokesperson for Chariot told ZDNet on Tuesday.
"Clearly that put a lot of strain on the site and slowed it down, but the site did not go down at any point," he added.
The spokesperson claimed that Chariot now had a "clear idea of the level of interest" and would upgrade their systems by next Monday's draw. He added that Chariot had "learned a lot" from the debacle.
Chariot claims Monday gives 30p per pound to charities, five times more than the National Lottery.