No members of the 100 Group, which represents FTSE 100 finance chiefs, support a vote for the UK to leave the European Union.
A survey of the 100 Group’s members, which also includes finance directors of non-FTSE 100 large UK private companies, found 53 per cent think the UK should stay in the EU, while 20 per cent have a neutral view.
The number voting against Brexit rises when they were questioned on their personal view, with 60 per cent saying the UK should remain.
The members, which collectively employ 2.1m people and spend £30.3bn on capital investment in the UK, say Brexit would lead to business instability and would put at risk trading relationships.
Simon Dingemans, chairman of the 100 Group and chief finance officer at GSK, says: “It is clear that finance directors have real concerns about the potential implications of a Brexit for their businesses and also importantly for consumers. In every sector there are implications from energy pricing to the services sector and the automobile and aerospace industries.
“Finance directors are also concerned about the potential instability for businesses that would follow a Brexit, particularly in relation to our trading relationships and long-term attractiveness of the UK.”
The 100 Group research found around a third of members have tried to quantify the impact of a Brexit on their business, with the cost ranging from no significant impact to hundreds of millions of pounds.