Supplies of Scotland’s other national drink could be affected this summer as the threat of strike action looms.

Around a dozen drivers at the AG Barr production and distribution centre in Cumbernauld, North Lanarkshire, are being balloted on walkouts after rejecting a 5% pay offer from the drinks giant.

AG Barr makes Irn-Bru, which is widely considered to be Scotland’s second national drink after whisky.

Unite the union says the offer equates to a pay cut of 6.3% based on the current retail price index of 11.3%.

The ballot opens on Thursday and will close on July 6.

Unite general secretary Sharon Graham said: “Imagine a hot summer in Scotland and no supplies of Irn-Bru – Scotland’s other national drink – to quench raging Scottish thirsts.

“Well that’s exactly what’s on the horizon if the management of AG Barr don’t revise their current wage offer to Unite members.

“It is a cash-rich company with £52.9 million sitting in the bank, so they have the money to make a decent offer. Our members can be assured that they will have Unite’s total support in this fight.”

The union claims the company’s has adjusted profit before tax of £43.5 million, and due to strong revenue generation it reported a net cash position of £52.9 million.

Andy Brown, Unite industrial officer, said: “Unite’s members keep the Cumbernauld factory of AG Barr running smoothly. Without them it will undoubtedly have a big impact on production and distribution.

“It is the first potential dispute in the history of the Cumbernauld factory, which goes to show at how angry our members are at the pay offer on the table.

“We are demanding that AG Barr get back round the table and make our members a fair offer, or else the supply of brands such as Irn-Bru could be hit by any strike action this summer.”