First Class Return By Rail to Scotland Offer

Spotted this offer from National Express who took over the East Coast route from GNER.

Though there may well be some limits on the usage of the travel vouchers being offered, I didn't spot anything immediately in the t&c.

Paul

It seems that they are subject to availability but as long as the seats are open, they are there to be taken.
If one were to book a Ryanair flight for a fiver, do online check in but not actually fly and send them the stub of the print out, do you think that they would accept that?
If they will then I think it makes sense to gamble a fiver on getting seats when you want them! Especially if they are first class. Even VS don't have a First Class....