Labour is on course to gain four councils in the council elections on Thursday, May 5.
Plaid Cymru could lose 42 seats, according to the poll. The poll, by Electoral Calculus and Find Out Now, suggests Labour will take back Bridgend and Merthyr Tydfil - two councils they lost five years ago - and gain Carmarthenshire and Flintshire. The poll suggests Labour would also take back Blaenau Gwent, the third council it lost in 2017.
All eyes will be on the election results as to the impact on the Conservatives and whether a drop in Tory support adds pressure to Boris Johnson. The only Welsh council currently held outright by the Conservatives is Monmouthshire which the poll suggests would remain in Conservative control. The Conservatives currently have 14 councillors in Vale of Glamorgan — one more than Labour who run the council with Independent councillors — and the Tories ran the council from 2017 until 2019 when a split in the local Tory group ended up with power switching hands. The poll has that authority returning to Conservative control. You can read the background of the split here.
Read more: All you need to know about elections in Wales on May 5
Plaid Cymru currently only has overall control of Gwynedd council. It currently has the most seats on Ceredigion council but fell short of an overall majority. Ynys Mon council has a Plaid Cymru leader and runs the authority with the support of independent councillors. The poll projects the party would keep Gwynedd, but Carmarthenshire, where there is a Plaid/Independent coalition would go to Labour.
This election will see boundaries change which means 1,234 councillors will be elected in Wales' 22 councils. Already, 74 councillors have been elected after they stood unopposed. You can read about that here. Community council elections are also taking place.
Previous polling was updated on May 3 including the results of 2,148 adults was conducted between 27-28 April for councils across England and Wales.
The poll predicts that Labour will benefit from a 6% swing with voters ditching the Conservatives and Labour could gain 16 councils across England and Wales. Conservatives could lose several councils, including the flagship City of Westminster, and could end up with less than 40 councils.
Martin Baxter, CEO of Electoral Calculus, said: "The renewed Partygate focus has made a poor situation for the Conservatives even worse by persuading even more Conservative supporters not to turn out at the local elections. The results could now be bad for Boris Johnson, especially if the Conservatives lose many hundreds of council seats and key flagship councils like Wandsworth or Westminster."
"And these results would also be good for Keir Starmer, who needs to get his first real electoral gains since becoming Labour leader. The opposition doesn't normally win a general election without winning other elections first, and Labour have to show that they can do that."
Chris Holbrook, CEO of Find Out Now, said: "Our poll suggests it will be a rough night for the Conservatives on Thursday, in particular the loss of the City of Westminster will be symbolically difficult for Boris Johnson. It might have other Tories jostling for position to replace him, even more than some in the media suggest they are already. Local election results don't always translate to general elections, of course. The Tories will try to argue that this is a blip driven by Partygate. Labour will suggest it is a true shift in opinion due to scandals and the cost-of-living crisis."
