Source is here: https://yougov.co.uk/topics/politics/survey-results/daily/2025/02/20/c33bd/1
That source allows you to see the results according to political affiliation. Pluralities of supporters of the Conservatives, Labour, and Lib Dems think that supporting Ukraine is more important.
The exception is Reform UK, whose supporters think that good relations with the USA are more important than supporting Ukraine.
Why? Do they have credibility or other issues?
Yes, they only attract a certain kind of users (i.e. easily tricked by “bonus points” systems). It’s an opt in rather than a random selection. Even if they claim to use common strategies to spread out the responses statistically, there is no way it is accurate.
YouGov bad: https://undark.org/2024/06/26/trolls-polls-survey-science/
YouGov good: https://blogs.lse.ac.uk/politicsandpolicy/poll-of-polls-mrp/