That assumes fair and lawful elections, which is far from given.
First, the election system itself, known and first-past-the-post, allows a party to win a seat with having a minimal majority in the ward. We don't have to look beyond the most recent election, in 2019, where the Tories won 365 out of 650 seats (56%) while only winning 43.6% of the voters. [0] A proportional voting system would make the ratio much more realistic [1], but I don't see that happening any time soon. (Ultimately, any government with the power to change the system would have been elected using that old system, so what change it?)
Second, the Tories are doing everyithing they can to improve the chances to win as many seats as possible. For example, the recently introduced photo ID requirement - in the country that traditionally eschews any mandatory photo IDs - is heavily skewed towards Tory voters: many poor people can't pay the fees to get a passport and don't have a driving license; and while senior public transport passes are accepted, student IDs and transport passes are not; and so on.
[0] https://www.bbc.co.uk/news/election/2019/results
[1] https://www.electoral-reform.org.uk/how-the-2019-election-re...