I know others might beable to help with more up to date info. But in 2007, I traveled to the UK for 6 weeks, then again a month later for another 6 weeks, then back one week and returned again with a work visa (had to go to the NYC Cons Office to get it stamped) and was fine.
I was indeed visiting during those times, I didn't tell them I was going to get a work visa because honestly you never know if everything is going to go through in that length of time even though I was pretty sure that the last visit was going to be the last before the visa... if any of that makes sense.