The latest ICM tracker poll for the Guardian, published on Wednesday, suggests that a growing number of British people now believe that Brexit will have a negative economic and social impact on life in Britain.
According to the poll:
The findings are the most negative ICM have found since they began tracking public opinion on Brexit since the EU referendum in 2016.
The shift appears to be driven largely by Remain supporters who have become increasingly negative about Brexit since the vote. However, ICM has also found Leave voters becoming increasingly unsure about its impact.
"Across all three statements, there’s an indication that the increase in overall negativity could be attributed to increasing negativity among those who voted remain in 2016, while those who voted leave look increasingly unsure about the likely impact of Brexit, answering ‘don’t know’" ICM’s Alex Turk said in a statement.
"This last finding – of possible increasing uncertainty on the impact of Brexit among leave voters – is something to watch out for over the coming months. If Remainers become increasingly certain that Brexit is a bad idea, while leavers waver more and more, then interesting times lie ahead."
The findings come as pro-EU groups mobilise in an attempt to keep Britain in the EU.
The George Soros-backed anti-Brexit group Best for Britain is set to lay out its detailed plans for stopping Brexit to coincide with the one-year anniversary of Theresa May's failed general election campaign next month.