A couple who claimed the massive £148.6 million EuroMillions jackpot on Friday are expected to tell of their plans for the future as they celebrate their win.
It was revealed on Monday that the pair are from Haverhill in Suffolk, but their identity has been kept a closely guarded secret.
They are due to go public on Tuesday when they accept a super-sized cheque, which will make them the nation's second-richest lottery winners.
The couple come just behind Colin and Chris Weir from Largs in North Ayrshire who won £161 million last July.
The difference in their prize fund is down to exchange rates.
A National Lottery spokesman said: "A couple from Haverhill, Suffolk, have won the UK's second-biggest ever lottery prize.
"They were the only winners in Friday's EuroMillions draw and have banked an amazing £148,656,000."
Theirs is the seventh lucky ticket to have hit the jackpot in the UK this year.