I think you will find that it is the ESCI Backfire re- boxed.
Quite a lot of it going on at the moment.
I recently purchased the Revell Victor - the Matchbox kit re-boxed.
A terrible kit but a must have for any RAF enthusiast.
Most of the Airfix new releases in 1/48 scale are Arii / Otaki moulds
which is generally better than the Airfix offerings.
Worst case scenario - the SM79 is the Airfix kit re - boxed!