For more than 150 years the battered red dispatch box held aloft by the chancellor of the exchequer on Budget Day had been considered the only one of its kind.

The famous box – its contents set to guide the country’s economic fortunes for the year ahead – was long thought to have been a one-off, made in 1860 especially for the then-chancellor William Gladstone.

It remained in use until it was finally retired in 2010 amid fears that it was simply falling apart through old age.

But it has now emerged that the famous budget box may not have been the only one made for the occupant of Number 11 Downing St.