The National Lottery website has crashed under pressure from thousands of users trying to buy last minute tickets for the Wednesday night Lotto draw.
The £50.4m jackpot is the largest in UK history, beating the previous record of £42m which was shared between three ticket holders in January 1996.
It is the total result of 13 consecutive rollovers after new rules introduced in October lifted the previous limit of four.
The unprecedented prize has led to a flood of last minute demand for online tickets causing the website to run slowly.
It is thought around 200 people a second will buy a ticket before sales close at 7:30pm.
A spokesman for the National Lottery told the Guardian that the website was running slowly in the face of "massive demand".
He said people could still buy tickets in shops.
The new rules mean if a winner is not found tonight, the rollover jackpot must be won on Saturday.
If no one has all six main numbers at the weekend draw the prize will be shared between players who have matched five of the main numbers and the bonus ball.
The draw will be broadcast live on YouTube at 8:30pm and you can follow all the coverage here.
The number of winners is unlikely to be announced before 9:30pm as the results will need to be independently audited and verified.
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