Builders in England have uncovered $2.5m bank notes stashed during World War II beneath the floorboards of Winston Churchill’s favourite tailors.

The dirt-smeared notes were discovered by renovators. The cash was hidden in a chest under a shop in Brighton, reports The Times.

It is believed the £1 and £5 bank notes were buried in 1940 at the height of fears Nazi Germany was about to invade Britain.

The face value of the hoard is estimated to be £30,000 ($53,000), but with inflation its value today would be £1m ($2.5m).

From 1936 to 1973, a branch of top London couturier Bradley’s was located on the site.

Bradley’s was one of the leading fashion houses favoured by Britain’s high society in the 1930s – including Winston Churchill and his wife Clementine who purchased fur clothing there.

And in the 1950s, the company’s furs were worn by French actress and sex symbol Brigitte Bardot.

The stash - which was discovered last month – includes notes with a distinctive blue design indicating they were issued as wartime emergency currency.

Police are holding the money while they investigate the discovery.