The prime minister has been pushing the old Conservative chestnut that pay rises should be linked to “productivity” – meaning for him that as long as the rich get richer the system is working (Pay rises should be a ‘reward for productivity’, says Rishi Sunak, 16 August). Conservatives worldwide push this mantra, but only as far as it benefits the rich. Does Rishi Sunak want to apply this philosophy to prices, rent and transportation? Only if the electricity costs less per kilowatt, or does more per kilowatt, can companies raise prices. Only if the house gets another bedroom can landlords raise prices. Only when the train is faster and less crowded can the fare increase. I agree with the prime minister. Only if the loaf of bread is bigger should the price rise. But I suspect that Sunak’s “reward for improving” philosophy is limited to those areas that benefit the rich, and he is not in favour of applying his rule to other areas of costs. John Benton Surfers Paradise, Australia • Few people would disagree with Rishi Sunak’s recent statement: “I want people to be paid more, but that means we have to have a growing economy where productivity is rising.” However, it raises the question: why is he pressing on regardless with Brexit, a policy that has a substantial adverse impact on the growth of both the economy and productivity? The Office for Budget Responsibility monitors the impact of Brexit and consistently forecasts that productivity will be 4% lower in the long run than if the UK had remained in the EU. Following Sunak’s own logic, the reality is that, until such time as the UK is again in the single market, with or without full EU membership, people’s potential pay will be significantly curtailed – one of the many “prices” of Brexit. David Newens Great Linford, Milton Keynes • In light of Rishi Sunak’s statement that pay increases should be linked to improvements in productivity, I wonder what improvements in MPs’ productivity would account for the increase in pay over the last 10 years from £66,396 in 2013 to £86,584 for 2023? It can hardly be the amount of time and effort dedicated to serving their constituents. Ian Simpson London • Have an opinion on anything you’ve read in the Guardian today? Please email us your letter and it will be considered for publication in our letters section.