McDonald's stores in Glasgow and the west could be hit with supply shortages as animal rights protesters continue to blockade all four UK distribution centres.
The fast food chain currently uses the four distributors to supply its 1,300 UK stores but lorries are being stopped from leaving with supplies by Animal Rebellion.
McDonald's has apologised to customers for "any disappointment caused" due to blockades .
Animal Rebellion, who claim the action will impact roughly 1,300 restaurants, are using trucks and bamboo structures at distribution sites in Hemel Hempstead, Basingstoke, Coventry and Heywood, Greater Manchester, to stop lorries from leaving depots.
The group is demanding McDonald's commit to becoming fully plant-based by 2025.
A McDonald's spokesman said: "Our distribution centres are currently facing disruption.
"We are assessing the impact on deliveries to our restaurants and to menu items.
"We apologise to our customers for any disappointment caused."
Animal Rebellion said they intend to remain at the sites for at least 24 hours, causing "significant disruption" to the McDonald's supply chain.
In a video posted on Twitter, a protester in Coventry said the demonstration "feels like the absolutely right thing to do".
She added: "We are in the middle of a climate and ecological emergency and we are still consuming huge quantities of meat on a scale that is just not sustainable for our planet."
Greater Manchester Police said officers at a demonstration in Heywood are helping to "maintain safety whilst facilitating the right to peaceful protest" and "there is minimum disruption to the local community".
James Ozden, a spokesman for the protest group, said the action is aimed at calling out the animal agriculture industry for its part in the global climate crisis.
He said: "The meat and dairy industry is destroying our planet: causing huge amounts of rainforest deforestation, emitting immense quantities of greenhouse gases and killing billions of animals each year.
"The only sustainable and realistic way to feed ten billion people is with a plant-based food system. Organic, free-range and 'sustainable' animal-based options simply aren't good enough."
