Boris Johnson's Tories still have a double-figure poll advantage over Labour as the parties rally in the last weekend before the election.
Though Labour has closed the gap in some surveys, a seven day average from PA Media still puts the Conservatives 10 points ahead.
It leaves the Tories on 43 per cent and Jeremy Corbyn's Labour on 33.
The Greens and the Brexit Party stay on three per cent each, while other parties make up the remaining five.
It comes as political leaders use the final weekend before December 12 to push for as much support as possible at the polls.
Culture secretary Nick Morgan said the suggestion must be taken "very seriously", while Labour has insisted it was in the public interest to release the documents - and there has been no indication they are not authentic.
Mr Corbyn and Mr Johnson push on after clashing in a leadership debate last night, which the Tory leader narrowly won with 52 per cent to 48 per cent giving him the advantage, according to a snap YouGov poll.
However, Mr Corbyn was judged the more trustworthy by a margin of 48 per cent to 38.
With less than a week to go to polling day on Thursday the findings suggest that the debate is unlikely to prove a game-changer.