Northern Ireland will suffer if Britain decides to leave the European Union in 2017, a leading economist has warned.

Alan Bridle, chief economist at the Bank of Ireland, said that a so-called Brexit would “negatively affect” the province, while forecasting that the odds of the UK departing are “one in eight”.

Speaking at a Bank of Ireland briefing, he said that leaving the EU would have a detrimental impact on Northern Ireland’s attractiveness to US investors, because positioning themselves in Northern Ireland would “no longer give them unfettered access to EU markets”.

However, Andrew Webb, a consulting director at the OCO consultancy, disagreed. “If the UK exited but remained part of a free-trade block, there would appear to be no practical reason for investor flight or fright.

That said, perceptions count for so much in inward investment.” Mr Webb conceded that, when OCO surveyed 200 company chiefs who have invested in the UK, half said they would reconsider their investment in the event of Britain leaving the EU.