I agree there is some demand for BLK/Jersey, but not enough to fill a 737 or even pay for the crew and fuel.
Spot on Ernest Lancs.
The average load factor for May to July this year has been 54.2% compared with 67.1% for the same period last year and 72.4% for the full summer period last year.
Even based on last full summer's load factor, Jet2 obviously feel that their aircraft can be better utilised on other routes.