The guy who done the alignment was thorough and said bushes seemed ok, but would benefit replacing as it's knocking 75k. If it were bushes, I'd have noticed it more on the last wheels/tyres too. All of them don't just go at once.
A evening jolly and I can confirm it does feel better, but the light still comes on in certain circumstances, even in 3rd. The power is not cut though, so is it just braking the corners? I'll redo the tyres when cold tomorrow, but they should currently be 33/36.