Opinium say it's the first time a leader of the opposition has been ahead since they started polling in 2015. Yougov's Chris Curtis reckons it's since 2007 across reputable polling for a Labour leader. Lisa Nandy would be 20 points ahead though so meh.
From
Opinium:
"Looking at seats gained in the 2019 election, Starmer leads on the best Prime Minister question amongst Labour seats in England and Wales that the Conservative gained in 2019; 41% think Starmer would make the best Prime Minister compared to 33% who think Johnson does."
"How respondents voted in 2019, in seats the Labour has lost since 2005 only (excl Scotland):
Con: 50%
Lab: 35%
Voting intention among those voters this week:
Con: 43% (-7)
Lab: 43% (+8)"