Millions have rushed to buy tickets for this Saturday's Lotto draw in the hope they can cash in on the first-ever triple rollover.
Lottery ticket retailer Jag Sanghera is having a punt
The promised prize money of at least £21.5m has prompted a huge rise in sales, said operator Camelot.
By Saturday lunchtime, tickets for the main draw were being sold at about 4m per hour, the company said.
No-one picked the winning six jackpot numbers in the last three draws on 19, 22 or 26 May.
If you won you could buy...
All 400 cars on display at this weekend's Birmingham Motor Show and still have £6.5m to spare
About 820 transatlantic crossings in the best suite on the Queen Mary 2
1,790kg of Almas golden caviar - once reserved for Russian Tsars (if that amount were obtainable)
Not the most expensive house in the world, bought for £70m in west London
Not the world's priciest painting, Garcon a la Pipe, sold for £104m
You would be given a session with a financial advisor and a legal advisor by Camelot
Jag Sanghera, 27, who manages his family's off-licence, DS News in Shepherd's Bush, London, told BBC News Online: "There has been a big rush for tickets all day. There is loads of excitement.
"People who have not played the game for ages are coming in and saying 'I must have a go at the rollover!'
"Other regulars are laying out double the amount of money they usually spend. I've even had a go myself."
Lottery fan Pat Kiernal, 62, said: "I'm really hoping to win.
"I've got a wife, two daughters and two grand-daughters and they can all expect a nice chunk of cash if I scoop the jackpot.
"Then I might just treat myself to a little drink."
Shepherd's Bush resident Sharon Kelly, 27, said: "If I won I'd help out my family and charities."
Andrew Andersz from this weekend's Motor Show in Birmingham said a single winner could buy all 400 cars at the show - the most expensive being a Mercedes SLR McLaren valued at £313,465 - and still have £6.5m to play with.
A spokeswoman for Camelot said they expected almost 60m Lotto tickets would be bought by the close of play on Saturday, equivalent to one for every person in the UK.
The ticket sales at their peak of 4m an hour amount to about 66,000 purchases a minute or 1,100 a second, she said.
It is the first time the jackpot has gone unclaimed for so long in the 879 draws made over 10 years.
There have been 131 rollovers and 14 double rollovers.
TOP FIVE LOTTO WINS
1st: £17,880,003 - 10 Dec 1994
2nd: £16,627,894 - 2 Jan 2002
3rd: £14,126,168 - 7 Sep 1997
4th: £14,003,369 - 28 Nov 1998
5th: 14,002,870 - 6 Jan 1996
If one person scooped the jackpot it would be the biggest single win on the game since the Lottery was launched in 1994.
The previous record for a single ticket winner was £17.8m in December of that year.
The odds of winning the jackpot are nearly one in 14m.
The biggest jackpot ever won was £42m in January 1996, which was shared by three ticket holders.
Around one third of jackpot millionaires still carry on working, according to Camelot, and the total number of new millionaires created by the National
Lottery is more than 1,600.