Standard life chairman Sir Gerry Grimstone and Weir Group chief Keith Cochrane have backed the case for the UK to stay in Europe.
A string of whisky industry chiefs and small business leaders north of the border have also backed a Remain vote tomorrow.
Across the UK, Virgin Group founder Sir Richard Branson and Michael Bloomberg, the former New York mayor, have endorsed the open letter. They claim it shows business is behind staying in the EU, despite claims from the Leave camp that industry is split.
The letter states: “We know our firms are stronger in Europe. Our reasons are straightforward: businesses and their employees benefit massively from being able to trade inside the world’s largest single market without barriers. As business people, we are always looking to the future – and a future inside the European Union is where we see more opportunities for investment, growth and new jobs.
“We know that Britain leaving the EU would mean having to re-establish terms of trade from scratch with our home market of 500 million consumers. That wouldn’t just hurt exporters but the hundreds of thousands of small and medium firms who do business with them.
“Even those that want Britain to leave say that, in the short term, Brexit would lead to economic uncertainty and would put jobs at risk. Smaller businesses and the people they employ are particularly vulnerable to any economic shock which could follow a vote to leave the EU.”