Want to keep up to date on Welsh politics? Sign up and get political news sent straight to your inbox Thank you for subscribing We have more newsletters Show me See our privacy notice Invalid Email

Most voters in every constituency in Wales support the demand for the people to be given the final say on the outcome of the Brexit negotiations, according to a vast new YouGov study based on polling almost 26,000 people.

The poll comes after a separate study for Cardiff University and ITV Wales showed that the nation would now back Remain if the referendum was re-run today.

The findings of the major YouGov study, which are expected to have a significant impact on the parliamentary battle over Brexit in the coming months, are based on the same polling model that confounded conventional wisdom and correctly predicted Labour’s surprise success in last year’s General Election.

Data scientists using the Multi-level Regression and Post-stratification (MRP) technique have produced an analysis that shows a total of 585 seats out of 632 surveyed – excluding Northern Ireland – back a People’s Vote.

The technique proved far more accurate than conventional polling in helping them predict the outcome of last year’s General Election.

Support for a People's Vote across Wales Aberavon 62.8% Aberconwy 56.2% Arfon 62.5% Alyn & Deeside 57.7% Blaenau Gwent 61.4% Bridgend 58.5% Brecon & Radnor 54.0% Caerphilly 61.1% Cardiff Central 70.3% Cardiff North 59.5% Cardiff South & Penarth 63.7% Cardiff West 63.0% Carmarthen East & Dinefwr 56.5% Carmarthen West and

S Pembs 53.7% Ceredigion 61.3% Clwyd South 57.4% Clwyd West 54.5% Cynon Valley 61.2% Delyn 58.7% Dwyfor Meirionnydd 53.6% Gower 56.5% Islwyn 60.1% Llanelli 59.9% Merthyr Tydfil & Rhymney 61.9% Monmouth 54.4% Montgomeryshire 54.1% Neath 59.6% Newport East 59.7% Newport West 58.5% Ogmore 61.2% Pontypridd 61.5% Preseli Pembrokeshire 54.8% Rhondda 63.5% Swansea East 61.1% Swansea West 63.0% Torfaen 58.9% Vale of Clwyd 57.4% Vale of Glamorgan 55.7% Wrexham 58.3% Ynys Mon 58.3%

The separate Welsh Political Barometer poll, carried out by YouGov for ITV Wales and Cardiff University’s Wales Governance Centre, shows that in a new referendum, 45% would vote to Remain and 41% to Leave, with 6% saying they would not vote and 7% saying they did not know how they would vote. The figures do not add up to 100% because of rounding.

These results compare with a five percentage point lead for Remain at the last poll in July.

In a hypothetical three-way referendum, with the options of Britain remaining in the EU, leaving the EU with a deal proposed by Theresa May, or leaving the EU without a deal, Remain would be backed by 43% of Welsh voters, Leave with a deal by 17% and Leave without a deal by 25%. In addition, 5% said they would not vote and 11% said they didn’t know how they would vote.

On the issue of whether there should be a further referendum, 40% would support having one, 45% would be against having one and 15% said they didn’t know.

How Wales would vote today YouGov

Professor Roger Awan-Scully of Cardiff University said: “Things continue to be very close between Remain and Leave, and there is no advance on the five-point Remain lead in the July poll – which had equalled the largest Remain lead in any Welsh poll since the referendum. All the difficulties associated with Brexit are emphatically not leading to a surge in public opposition to the UK leaving the EU.

“It is striking that the position of the Prime Minister is the least popular of the three options. And when we look only at Conservative supporters, there is little more support for Theresa May’s position: among those respondents indicating that they would vote Conservative in a general election, only 28% backed the ‘Leave with deal’ option, compared to fully 51% who favoured Leaving the EU without any deal.

“Once the second preferences of those support the Prime Minister’s proposed deal have been taken into account, and leaving out those who chose Don’t Know, we arrive at the following outcome: Remain: 56%, Leave without deal: 44%.”

Video: Countdown to Brexit 143 days to go...

Video Loading Video Unavailable Click to play Tap to play The video will start in 8 Cancel Play now

In the event of a “no deal” outcome to negotiations, there would be an outcome after excluding those who would not vote and those who don’t know of 54% Remain and 46% Leave.

Asked whether it was worth jeopardising the Northern Ireland peace process to “take back control”, 58% said it wasn’t and 42% said it was.

However, some 72% of Conservative voters thought it would be worth jeopardising the peace process to secure Brexit.

Overall, 51% of Welsh voters thought securing Brexit was worth risking the break-up of the UK with a vote for Scottish independence. So far as Conservative voters are concerned, the proportion concerned was as high as 90%.

Prof Awan-Scully said: “We should exercise some caution in interpreting the responses to these questions. They ask quite a lot of respondents – a hypothetical situation that requires a fairly substantial leap of the imagination.

"And on the second question it is not quite clear how, for instance, we might best interpret the responses of Plaid Cymru supporters and others who might rather like the idea of Brexit prompting Scottish independence.

"But particularly notable for both these questions are the responses from Conservative supporters. [These results] reveal the strength of feeling behind Brexit, and the extent to which the Conservatives have become the party of Leave. There is little doubt regarding which of the UK’s two unions they care about more.”

Fieldwork for the poll took place between October 30 and November 2, with 1,031 interviews taking place.

Cardiff Central MP Jo Stevens said: "Ever since the referendum result, the government’s incompetent approach, the adverse economic impact taking place weekly and our uncovering of illegality, cheating and electoral law breaches by some of the Leave campaign particularly through the work of our DCMS Select Committee has meant there is now a majority across the country in favour of a people’s vote.

"My constituents in Cardiff Central have been absolutely and overwhelmingly clear throughout, that Brexit is a disaster and that everyone should have the opportunity to put a stop to it.”