The poll, carried out by the Times, showed that 37% of Leave voters believe Brexit has a been a failure, with just 20% saying it a success and 35% sitting on the fence.
Since the leave vote was 52% that is roughly half so 18% overall.
I was more thinking about the line on Tory voters at the end. 38% against, 22% for, leaving 40% on the fence.
Although, typing it out I just realised I did the maths wrong in my head. I thought it was 50%. Either way, it's still a large portion of people undecided.