I think Flightrider is correct - Air India operated A310s to Manchester for a couple of years in the 90s, but pulled off because they wanted to use the aircraft elsewhere, which suggests that regulatory approval is already there. Presumably bmi would need to acquire a 4th (at least) 330 for all this, especially if the Caribbean routes are planned to continue next summer:
1 aircraft for daily Chicago
1 aircraft for daily Toronto (in the summer at least)
1 aircraft for Washington (and India?)
1 aircraft for the Caribbean
Interesting times.....