Royal Mail bosses have been criticised for leaving a Edinburgh postbox unchecked for almost a month, leaving letters and referendum registrations spilling onto the pavement.

Customers said their electoral roll documents were left lying on the ground after the box on the Royal Mile became jammed with undelivered mail. Royal Mail said the letterbox in question was supposed to be sealed shut throughout the month, because of limited traffic access during the festival.

But staff discovered its seal had been broken.