By Levi Winchester Martin Lewis has issued an urgent “do it now” warning over a big change coming to the Nectar loyalty scheme in just under two weeks. The number of Avios – the reward currency of the British Airways Executive Club – you need to convert into Nectar points is changing. At the moment, every 300 Avios you swap will get you 400 Nectar points, which is worth around £2. But from March 11, you will need to convert 400 Avios points to get the same 400 Nectar points, according to MoneySavingExpert.com (MSE). In a post published on X/ Twitter, Martin said: “Got Avios points? Currently t…