P&O Caribbean flights

I've booked a P&O Caribbean fly cruise in November. I'm reluctant to pay £20 each way to book a seat. Last time I flew with Thomson (in May) I was able to check in and book seats within 7 days of flying without charge. Obviously I would have to take pot luck on what seats are left but does anyone know if this option is available on Caribbean flights. Has anyone had experience of doing this.

Did you try calling them and asking?

And since you don't say whether this is a scheduled flight or charter, or even what airline or what cities....the answer is a definite maybe.