Trade with the European Union is critical to 58% of the organisations in the 2015 CIO 100. With in excess of half of the organisations citing the importance of trade with the EU, a referendum on the UK's membership of the EU is highly risky.

The CIO 100 features 100 stories of major business transformation led by CIOs. In 2015 outdoors, cycling and motoring retailer Halfords topped the list alongside hotel chain glh, Hyperion Insurance, the Financial Times and the Clinical Research Network, part of the Department of Health.

The public sector, housing associations and two national charities were selected for the 2015 CIO 100, but 42% of organisations stated they did not trade with the EU.

The Conservative Party and the UK Independence Party (UKIP) both have a severe anti-European stance, in direct conflict with the evidence gathered by the CIO 100 survey. The Conservatives, who have led a coalition government since 2010 and led the UK to marginal influence in Europe states it will hold an in or out referendum in 2017 should it win power. While UKIP wants to exit the EU.

Organisations in the 2015 CIO 100 include international manufacturing giant Nissan that is a major employer in the North East, but also has manufacturing in EU states such as Spain. UK-owned JCB, a manufacturer of construction vehicles, is also represented. AstraZeneca, Shell, Diageo, Gatwick Airport and Unilever are just some of the organisations represented that trade with the EU.

Editor in Chief of CIO UK Mark Chillingworth said: "It is worrying that politicians are seeking to put 58% of organisations that are in the CIO 100 at risk of increased barriers to trade. This furthers the view that today's politicians are out of touch with people and business.

"It is clear that the EU needs major reform, just as our own political institutions do, but you can only influence reform from the inside. The Conservatives and UKIP are playing a dangerous and risky game with referendum talk."