A poll commissioned for the Observer and carried out by Ipsos MORI, which drew responses from more than 600 economists, found 88% saying an exit from the EU and the single market would most likely damage Britain’s growth prospects over the next five years.
A striking 82% of the economists who responded thought there would probably be a negative impact on household incomes over the next five years in the event of a Leave vote, with 61% thinking unemployment would rise.
Those surveyed were members of the profession’s most respected representative bodies, the Royal Economic Society and the Society of Business Economists, and all who replied did so voluntarily.
Paul Johnson, director of the independent Institute for Fiscal Studies, said the findings, from a survey unprecedented in its scale, showed an extraordinary level of unity. “For a profession known to agree about little, it is pretty remarkable to see this degree of consensus about anything,” Johnson said. “It no doubt reflects the level of agreement among many economists about the benefits of free trade and the costs of uncertainty for economic growth.”
The poll also found a majority of respondents – 57% – held the view that a vote for Brexit on 23 June would blow a hole in economic growth, cutting GDP by more than 3% over the next five years. Just 5% thought that there would probably be a positive impact.
The economists were also overwhelmingly pessimistic about the long-term economic impact of leaving the EU and the single market. Some 72% said that a vote to leave would most likely have a negative impact on growth for 10-20 years.
Just 4% of respondents who thought Brexit would mostly likely have a negative impact on GDP over the initial five years said it would have a positive effect over the longer term.
The findings – which come as 37 faith leaders write in a letter to the Observer warning that Brexit will damage the causes of peace and the fight against poverty – will bolster David Cameron and George Osborne, who have both argued strongly that the economy will be hit hard in the event of Brexit.
Read more: Economists overwhelmingly reject Brexit in boost for Cameron | Politics | The Guardian