David Abercrombie, 26, from Irvine, said his colleagues thought he was joking after his Lucky Lines Yellow Scratchcard l revealed the top prize.
He said: “I scratched the card when I got to the site and I was completely stunned. I said to my workmate ‘I’ve won the top prize’. He didn’t believe me at first and took it off me to see for himself. Everyone was cheering when they realised I’d won.
“We went straight back to the shop and they checked again for me. They advised me to call the National Lottery line because it was such a big win.
“The worst thing was it was only 7.30am and I had to wait until 9am for the claim line to open. The minute the clock hit nine I was straight on the phone.
“After I’d spoken to Camelot, I signed the back of the scratchcard and put it in my pocket. I kept my hand in that pocket all day just in case.”
David has made plans for spending his windfall.
He added: “We will be buying a bigger house so my two little girls will get bedrooms of their own. I want to put some money away for their future. A new car is on the list too, something like a Mercedes, not too flashy.”