Monarch 28-29" Their premium economy = 34"
My Travel 29-30" Long Haul: 35" Premium Long Haul: 28" Short Haul
First choice long haul Star Class 33": Premier 36": Short haul 28"-29"
[I cannot believe that these are seat pitches - they are more like bicycle wheel sizes. I'm all in favour of leading the world and I acknowledge that the UK does this often, but I think you've picked the wrong thing to lead this time].