The flight stopped in Alicante as it had a tech fault and Jet2 have a large engineering presence at ALC. the divert was nothing to do with fuel.
So that ends the 'Jet2 using aircraft that haven't got the legs for it' debate as that is total tosh. As me mentioned by LBIA, Jet2 use the high MTOW and wingletted 737-300's on the canaries and turkey runs and these are more than capable of these runs, hence there has not been any fuel related diverts in months.
End of debate. All Jet2 aircraft from all bases are more than capable of operating their allocated routes so no fuel stops are planned. So no need to worry.