Consistently = enough that Politico's Poll of Polls UK (smooth view) shows any party polling at greater than or equal to 35%, for 14 days in a row, according to the day-by-day hover tool. Excepting any obvious data / charting errors on Politico's end. All 14 days must fall within 2025 I.e. the streak cannot start on Dec 31st 2025. Politico do take time to update their charts, so any 14 day period must remain in place for 14 days after it completes.
If for any reason Politico's Poll of Polls ceases to function then the backup metric is Wikipedia's UK Polling chart.
https://manifold.markets/AlanTennant/uk-governmental-approval-rating-amo?r=QWxhblRlbm5hbnQ
Theoretically the government in power should be the most popular one, ours (UK) was at 5% a few years ago, and still struggles to reach double digits.
Also see my more local one:
https://manifold.markets/AlanTennant/in-cambridge-uk-in-the-city-council?r=QWxhblRlbm5hbnQ