If Britain decides to leave the European Union on 23 June, the move could cost the UK’s tourism industry as much as £4.1bn a year in international tourist spending alone, new research has suggested.

The findings from Travelzoo, based on responses from almost 8,000 tourists, indicate that a third of travellers from Germany, Italy and Spain – and a quarter from France – say they would be less inclined to travel to the UK in the event of a Leave vote. Four in ten respondents from EU countries also worry that Brexit could make UK holidays more expensive.

The research suggested that the view of the four largest European Union nations (France, Germany, Italy and Spain) is that the UK should stay in the EU, with just under 70 per cent in the Remain camp. However, respondents from some nations – notably France – believe that leaving the EU could make the UK a safer destination for holidays.

Despite almost 75 per cent of the UK’s international visitors coming from within the EU, a small number of respondents from further afield (10 per cent of those from Canada and 12 per cent from the US) stated they would be less likely to come to a post-Brexit UK.

“Although the impact of Brexit on tourism is a difficult one to predict, given that France, Germany, Italy and Spain make up four of the UK’s top seven tourist-supplying countries, it’s likely that the net result of Brexit will be significantly negative for the UK economy,” said John Fletcher, pro vice chancellor at Bournemouth University – a leading institution in travel and tourism.

“While the figures above reflect only the direct tourism-related economic impacts of voting to leave the EU, if tourist spending from overseas visitors did indeed fall by £4.1bn per year, this is likely to reduce HMRC revenue by more than £1.1bn and reduce support for around 63,000 jobs in the UK.”

With the vote on Britain’s EU referendum on 23 June edging closer and polls suggesting the outcome is on a knife-edge, concern has been growing that Brexit could be bad news for the tourism and hospitality industries.

The chief executive of the Institute of Hospitality, Peter Ducker, has warned that Brexit could lead to a significant labour shortage for the sector, as a large number of workers come from abroad.

Meanwhile, the Tourism Alliance director Kurt Janson said in his Leisure Opportunities column on Brexit recently: “There is a significant risk that staff shortages will increase, forcing up wage costs for businesses and possibly lowering the quality of service provided to customers.”