The most recent poll in the YouGov, WhatUKthinks series has just been published this week (HERE). This is in answer to the question: In hindsight, do you think Britain was right or wrong to vote to leave the EU? It's the 67th and shows WRONG on a 44% but RIGHT is just behind on 43%. A 1% lead unchanged from last week.
Total No of polls since August 2016: 67
Polls with RIGHT IN THE LEAD: 28 - (22 in the first 27 polls)
Polls with WRONG IN THE LEAD: 31 - (24 in the last 25 polls)
Even: 8
Last time RIGHT was in the lead: 17th January 2018
Looked at annually:
2016 - (from August) 12 polls in total WRONG =1, RIGHT 11
2017 - 39 in total WRONG = 15, RIGHT = 17
2018 - (to date) 16 in total WRONG = 15, RIGHT = 1