We travelled First Choice Premium in February this year, when you get your reference number for extras log in, it will say you can only select seats 2 months before departure or to call a number, no point calling the number as they use the same web site to pre book and said 2 months too, same in First Choice shop. I logged on almost every day and suddenly struck lucky, 2 months prior to flight would have been 27th December and I think I managed to prebook seats about 2 wks before that, sorry don't have exact date. Just keep trying.

Just a tip when pre booking seats, our return flight was delayed and the plane was changed to one with a smaller Premium area, we were lucky as I'd pre booked row 4 so we were still seated in Premium rows 5+ were not so lucky although they did get the Premium food, drinks and entertainment and a refund on the return leg.

Enjoy your trip.

I'm surprised you managed to get 10 days, I thought First Choice / Thomson only flew once a week?

Are you sure it isn't a Monarch flight? They fly more than once a week.

It's definitely first choice:

Premium Class Service
Outbound London Gatwick
Goa (10hr 55mins)
Wed 02 Feb 2011
Check in:13:05
Departs: 15:05
Arrives: 06:00 on Thu
Airline: Thomson Airways
Flight number:TOM082


Premium Class Service
Return Goa
London Gatwick
Sun 13 Feb 2011
Check in:09:35
Departs:11:35
Arrives:16:50
Airline: Thomson Airways
Flight number:TOM053

Good flight times too!