I do wonder that the recent labour surge (OK, 2 polls showing a small narrowing of tory lead) has much to do with new voters, im assuming they are less likely to be captured by pollsters anyway
but
There have been 3,191,193 applications to register to vote in those 28 days, an average of 114,000 per day
That figure is 38% higher than the 2,315,893 applications to register in a similar period in the 2017 election, which equated to an average of 68,000 registrations per day
Of the applications made since the election was called in 2019, 2,125,064 applications (67% of the total) have been made by people aged 34 or under
and as younger voters are much more likely to vote labour/libdem/remain that may hurt the tories on polling day (or conceivably split remain vote further!)
Tories won popular vote last election by just 750,000 votes
so potentially giving labour a net boost of 1.5million votes
*of course FPTP & BXP/Tory pact very much skews all this & and is set against 2:1 swing of leavers to tory vs remainers to labour
Ultimately big surge in younger voters is hopefully giving Tories some squeaky bum time