Surely nobody on a full time contract elsewhere will be tempted?
They wouldnt be the first airline in the UK to sell the idea of a permanent job at their recruitment/assessment day, only to change it to a fixed term or summer only contract at the very last minute... with the notion of a permanent job end of summer... which then doesnt happen.
Its very easy to get caught up in a nasty cycle of summer only fixed term contracts, year after year - and unemployed 7 months of the year. I personally would never leave a permanent job for any fixed term contract, no matter how good the airline, ever again