Over two thirds of UK businesses are "not making adequate preparations" for the UK's withdrawal from the European Union, according to senior business leaders.

A third of respondents to the survey, which was carried out by Interim Partners, said Brexit was the biggest upcoming challenge for businesses.

However, 69pc of UK businesses are not preparing adequately for the regulatory changes thrown up by the Brexit process, according to those surveyed, meaning many businesses are likely to struggle with the fallout unless they start preparations immediately.

One respondent from the group said that businesses must "reassess their operating model and restructure to become more flexible... to adapt quickly to the shape and impact of Brexit becomes clearer".

The group was almost evenly split over the impact of Brexit on foreign investors – whether it would cause their investments to increase or decrease.

In light of the lack of preparation, turnaround specialists will be in high demand over the coming years, according to 41pc of the business leaders surveyed.