The bank has taken on a short-term lease on premises in Uddingston, south-east of Glasgow, and is reportedly developing plans for a purpose-built site.

A source at the bank said: “Nothing is a done deal until they start moving people, but Glasgow is cost-friendly, has a good workforce – and might be in the EU when independent.”

Barclays declined to comment on the website’s story, but told The National: “Barclays delivers a broad range of products and services to clients across most of the major economies in Europe at present – we value these relationships and our priority is to minimise disruption and preserve our clients’ ability to continue to transact with Barclays.

“While we remain confident of continued deep inter-linkages between EU and UK financial services markets, in the absence of certainty around the timing and composition of an agreement, we intend to take necessary steps to preserve ongoing market access for our customers.

“Barclays intends to utilise an existing licensed EU-based bank subsidiary to continue passported activity. Barclays Bank Ireland, which has a banking licence and which we have operated for almost 40 years, provides a natural base and we are engaging with our regulators in discussions to extend its activities.

“The final outcome of the negotiations between the UK and the EU and any settlement reached in respect of financial services remains uncertain, and as a result we stand ready to refine our plans in light of external developments and will continue to work closely with regulators, clients, colleagues and other stakeholders to ensure that we are able to respond appropriately to any outcome.”