Products from ready salted crisps to Quavers have been affected by a problem with an IT upgrade.

The firm says it is prioritising production of its most popular crisp flavours, but has not given a timescale for when stocks will be replenished.

The shortage of crisps has seen some empty shelves in the shops and prompted some online vendors to sell Walkers products at inflated prices on eBay, with reports that the snacks were selling for as much as £6 a packet.

In a statement, Walkers said: “Our sites are still making crisps and snacks, but at a reduced scale.

“We’re doing everything we can to increase production and get people’s favourites back on shelves. We’re very sorry for the inconvenience caused.”