I wasn’t sure what the situation was so googled re population
The UK population, which was estimated to be 67.1 million in mid-2020, is projected to rise by 2.1 million to 69.2 million over the decade to mid-2030 (3.2% increase). In comparison, between 2010 and 2020 the population is estimated to have grown by 4.3 million (6.9% increase).
it has increased, including immigration