North Ayrshire Council made the frank assessment in a report examining the possible impact locally if the UK crashed out of the European Union without a comprehensive agreement on trade in place.
The publication, compiled by council officers and shared publicly on the local authority’s website, noted that “food prices have already been going up as a result of Brexit”.
In a section marked food security, the report said here was a “question of whether [the council] might need to amend school nutrition standards”.
It said there was a “risk that manufacturers will provide all supply to retail, creating a shortage in the public sector”, while “suppliers will supply supermarkets rather than councils”.
Strict nutritional standards are designed to ensure that pupils are fed healthy meals while attending school.
The Scottish Government told The Scotsman that it was regularly speaking to local authorities regarding food supplies in the wake of a no-deal Brexit.
A spokesman for North Ayrshire Council said: “In common with other responsible local authorities, we have drawn together comprehensive contingency plans to ensure we are prepared in the event of a no-deal Brexit.”
Asked if City of Edinburgh Council had similar concerns to North Ayrshire, a spokeswoman said: “As part of our contingency planning for leaving the EU, in which we have been investigating and monitoring potential areas of risk so that we can prepare for them, we remain in regular contact with our main suppliers so that we can continue to deliver services to communities with as minimal disruption as possible.”
Research by the BBC found other councils across the UK have already expressed concerns about the provision of meals to pupils if supply chains were affected by disruption at ports.
One local authority in Tyneside said “special dietary requirements may be difficult to meet” and that “if fresh produce is difficult to come by” schools should “increase use of tins and frozen goods”.
Other councils have claimed prices for school meals will inevitably rise as a result of Brexit and that central government funding for free school meals will have to increase.
The UK Government said the food industry was “well versed at dealing with scenarios that can affect food supply”, adding: “We have a highly resilient food supply chain and consumers in the UK have access to a range of sources of food.
“This will continue to be the case when we leave the EU.”
Earlier this week Prime Minister Boris Johnson insisted preparations for a no-deal Brexit remained on track despite a leaked report warning of potential food and medicine shortages.
A Scottish Government spokeswoman said: “The Scottish Government is regularly engaging with colleagues in local government and across the wider public sector about food supplies in the event of a no-deal Brexit, including how this might impact upon the provision of food in schools.
“The current regulations allow flexibility for adjustment of menus to address most supply issues and to ensure that schools continue to offer a healthy, nutritious choice.
“The Scottish Government is making plans across the range of its devolved responsibilities to ensure that, as far as possible, we mitigate the impact of a no-deal Brexit, including working to safeguard the continuity of food supplies.
“However, it will not be possible to mitigate all the effects of a no-deal. The UK Government must change course to avoid inflicting very significant disruption.”