Labour has posted a 12-point opinion poll lead over the Tories - its widest margin of advantage in a ComRes survey for more than seven years.
The Opposition gained two points to 43% on a month ago and the Conservatives dropped two to 31%, in the poll conducted for the Independent on Sunday and Sunday Mirror.
It showed the Liberal Democrats static on 10% and Ukip down one on 8%.
More top news
Since Friday's EU result, the Liberal Democrats have recorded thousands of voters signing up to become members.
Anthony Joshua vowed to rest after retaining his heavyweight title.
Adele described performing at Glastonbury as the "best moment" of her life as she took to the Pyramid Stage.