The company which owns the soft drink, AG Barr, has announced it is to merge with rival Britvic, in a £1.4 billion deal.
The proposal could see as many as 500 jobs lost across the UK, but it has not been revealed where the axe will fall.
A spokesman for AG Barr said the company would retain its HQ in Cumbernauld, but could not confirm how many of the workforce there could go.
The majority of AG Barr's Scottish staff are based at Cumbernauld.
However, in a further concern over the future Scottish identity of the iconic brand, it has been revealed that the operational headquarters of the merged company will be at Britvic's main offices in Hemel Hempsted, in Hertfordshire.
Jamie Hepburn, MSP for Cumbernauld and Kilsyth, has now demanded clarity on how any cuts will impact on the North Lanarkshire operation.
Mr Hepburn said: "It is a positive development that the new company want to retain their base in Cumbernauld, obviously seeing the business benefits of remaining headquartered north of the border.
"What everyone will now be looking for is clarity on where the job losses will be coming from.
"The employees of AG Barr in Cumbernauld already have the relevant skills to enable them to excel at that location and as such should be viewed by Barr Britvic as an invaluable asset."
Hertfordshire-based Britvic, whose brands include Robinsons, Fruit Shoot, R Whites and Tango, has around 3300 staff. AG Barr, which dates back to 1875 and also makes Tizer and Rubicon, has just under 1000 employees.
It is believed the company will be looking to shed between eight and 12% of the new, combined workforce.
Britvic shareholders will own 63% of the new company – to be called Barr Britvic Soft Drinks – with AG Barr holding the rest. The deal is still subject to shareholder approval.
Barr has produced Irn-Bru from a secret recipe for more than 130 years.