No. Since bmi changed their business model, the A319 and even the A320 has often showed healthy load factors, what is affecting the route is the bmibaby departure, 90%, probably more, of all people I have spoken to don't realise that bmi and bmibaby are two different airlines and people have automatically assumed that the London Heathrow route has gone along with all the others.
This is why load factors have taken a nose dive. I would have thought that bmi taking over bmibaby's advertisment which appears prior to the ITV Weather would have helped, but obviously not. What they really need to do is plaster a load of advertisments on buses like GSM, LS and T3 do.