There are a few here defending the indefensible. I have lost count of the number of times some pillock in a brightly painted 319 has done this to me at a London airport. ATC should have sent them back to stand and cancelled their plan. Frankly, I'd like the pilots arrested. If you knowingly line up without being ready, unless you have mentioned that to ATC specifically and they still line you up, then you should be stripped of you licence. It's one thing to have a problem as you line up - pax standing up, a tech fault or whatever, it happens, but to deliberately block a runway out of selfishness is as unprofessional as it gets. To then refuse to vacate when instructed should result in the pilots' prosecutions. Time to start pruning out the bad from our profession. Maybe they could lose a few pilots who don't bother with preflight checks and then fly over the entirety of London on a single burning engine before bringing the country's biggest, busiest airport to a stop instead of lobbing in somewhere more sensible. These events show the world BA have the same problems as every other company - shame it's only BA pilots that can't see it.