If a single ticket scoops the top prize in Tuesday’s EuroMillions draw, it would create the UK and Europe’s biggest ever winner.
The current record holders are Colin and Chris Weir, from Largs in North Ayrshire, Scotland who won £161 million in 2011.
Andy Carter, the National Lottery’s senior winner’s adviser, said: “This jackpot is a record breaker.”
He added: “The extraordinary sum would be life-changing for the winner and we are poised to support them the moment they claim.
“Of course, we have champagne on ice ready to celebrate if they set a new record win.”
A £161 million jackpot would put the winner in joint 672nd on this year’s Sunday Times rich list, ahead of singers Robbie Williams, who is worth £150 million, and Sir Tom Jones, who is worth £160 million.
So far this year, UK winners have scooped five EuroMillions jackpots, with the biggest so far won by an anonymous ticket-holder, who banked £87 million.