London: Brexit has already damaged businesses even before Prime Minister Theresa May triggers the start of Britain’s withdrawal from the European Union, according to a survey of the country’s largest companies.

More than half — 58 per cent — of top executives at Britain’s biggest firms said the vote to quit the bloc has had a negative impact on their businesses, the Ipsos MORI “Captains of Industry” poll found. Two-thirds of the chief executives, chairmen and directors interviewed for the survey said they believed the business situation would worsen in the next 12 months.

“Business in this country is already feeling the pain of the economic upheaval of leaving the EU,” said Ben Page, CEO of Ipsos MORI. “According to respondents there is no sign that this is likely to ease this year.”

The research, conducted between September and December 2016, involved interviews with 114 chief executives, chairmen, managing directors and others from the FTSE 500 companies. It revealed the extent of business leaders’ underlying concerns over Brexit, despite positive economic data since the referendum vote last June.

The results could embolden lawmakers as they scrutinise the prime minister’s plan for Brexit negotiations in Parliament this week. May is facing a rebellion from Conservative members of Parliament who fear she will deny them a vote on her final Brexit deal until it is too late to negotiate better terms.

More than two thirds of respondents to the Ipsos Mori said they have responded to the referendum result, with actions including moving business outside the UK and looking at currency moves. The sharp drop in the exchange rate, while helping to boost the FTSE-100 share index, is squeezing companies’ margins by pushing up import costs.

The British Chambers of Commerce said Monday that a majority of firms expect their costs to increase over the coming year and plan to increase prices in response. Sterling has fallen 16 per cent since the Brexit referendum in June, and nearly as many exporters said the low pound was damaging them as those who said it was helpful.

The government’s skill in negotiating the final agreement with the EU will be key to mitigating the impact of leaving the bloc, according to the Ipsos Mori survey. Half of those interviewed were not confident in May’s ability to get the best deal possible.

Movement of workers was a key concern of those who took part in the study. When asked to state their priorities for the Brexit negotiations, 54 per cent cited access to skilled labour. Almost half — 47 per cent — called for securing free trade and access to the EU single market, with so-called passporting rights for financial services named by 16 per cent.

Consulting firm Mercer on Monday warned that gaps in Britain’s labour market will worsen as Brexit reduces the number of foreign workers coming to the UK. Migration is also proving contentious with May’s Conservative Party. Some senior members are unhappy about her stance on migrants’ rights, calling on her to make a unilateral promise to EU nationals living and working in the UK that they will not be thrown out of the country after Brexit.

Despite ongoing uncertainty, the majority of business leaders — 96 per cent — were confident their company can adapt to life outside the EU. Over a five-year period, almost one-third said they thought their business would start to feel the positive effects of leaving the EU. “Businesses are also ready to adapt in order to survive, and thrive,” Page said.