Guinness is raiding its reserves in Ireland to boost shipments to the UK, where a social media-fuelled surge in demand has left some pubs facing shortages.

The reserves – known as security stocks – are usually earmarked for Irish customers but are now being used to ease pressure on publicans in the UK who have struggled to keep up with new fans after a marketing push in recent years.

Some pub landlords have reportedly been using ration cards to ensure every customer gets a fair share of the stout.

Diageo, which owns Guinness, has also put shipments bound for North America on standby for potential diversion to the UK in case the security stocks fail to fill the gap, according to the Sunday Times, which first reported the reserves raid.

A spokesperson for Diageo thanked customers for their patience and said demand remained at “unprecedented levels”.

“We are producing more Guinness today than we ever have in our 265-year history, and we continue to work closely with customers across our network to manage Guinness distribution as efficiently as possible, ensuring we maximise supply and minimise disruptions for pubs and retailers,” the spokesperson said.

Diageo said it was buying time before it could roll out a “phased replenishment” in the new year that would help UK Guinness supplies return to normal.

The early 2025 restock is part of efforts to avoid an even more acute shortage, with the company anticipating a fresh rush for Guinness as sport fans gear up for the Six Nations rugby championship, which kicks off on 31 January.

Guinness has notably gained traction among women and young people, including gen Z, having traditionally been the favoured drink of older men and rugby teams. It follows a marketing push over the past few years that has involved working with influencers on social media to raise Guinness’s profile.

Celebrities have also fuelled the trend, with Kim Kardashian making headlines last year when she supped on a pint in a London pub. The singer Olivia Rodrigo made waves when she wore a “Guinness is good 4U” T-shirt when performing in Dublin this year.

The drink’s growing popularity has also been fuelled by trends such as “splitting the G”, a drinking game in which players try to get the line between the foam and stout to sit in the middle of the letter G on the Guinness pub glass after their first sip.

There has been some speculation that the shortage is merely part of a wider marketing stunt, though insiders have said the supply concerns are genuine.

Earlier this month, Diageo was said to be unable to increase supply from its Dublin brewery, which was already working at full capacity.

It is hoped the shortage will be temporary, given Diageo has been pumping money into its St James’s Gate brewery in the Irish capital and is also building a new €200m (£166m) brewery in County Kildare.