Mr Dawes, 47, a shift supervisor for Premier Foods, and Ms Dawes, 43, a volunteer with the British Heart Foundation, had played the EuroMillions draw only twice before.
"We won't be keeping our one-bedroom flat," said Ms Dawes, who has already taken her partner's surname and is now planning the lavish wedding they could not previously afford.
Her £800 engagement ring is about to receive a multi-carat upgrade.
Mr Dawes, an avid fan of Chelsea Football Club, will buy a town house close to the club's ground at Stamford Bridge.
The couple, both previously married with grown-up children, also plan to use their good fortune to help others.
Mr Dawes said: "We've drawn up a list of 20 people who we are going to make millionaires - anyone who has helped us through our lives."
Mr Dawes told his shift manager he was unable to work on Sunday and has now officially "retired".
Ms Dawes said it would be too difficult to return to the shop where she volunteered until last week.
They agreed that they had come into an "excessive" amount of money and promised to support a number of children's charities.
- INDEPENDENT
