ComRes' latest poll, released today:
LAB 28% (-)
CON 24% (-1)
BRX 20% (+1)
LD 15% (-1)
GRN 5% (-)
SNP 3% (-)
UKIP 1% (-)
Other 3% (-)
(changes relate to ComRes/Daily Telegraph poll on 9th July 2019)
They also note "Two in five of those who voted Labour in 2017 (40%) say that Labour’s latest Brexit position would make them more likely to vote Labour at the next General Election, in comparison to just one in five 2017 Labour voters (21%) who would now be less likely as a result."
Of course, this is but one poll, and plenty can change before the GE actually comes along - but, it's encouraging that Labour's recent shift to supporting a PV in all situations - regarding May's deal or their own unicorn - appears to have had an effect.