Eurostar - FlyBE currently operate a winter charter MANALC and over the summer also have BHXAGP so the routes out of Southampton should be within reach of the 146. I accept that SOU runway is of a reduced length but FlyBE have even operated GCIAGP in the past with the 146-200 seating 97pax.
It may also suprise you that even the D8-Q400 can operate both SOUMJV and AGP routes if required but may suffer from a reduced payload on the return journey, and FlyBE currently operate BHXBRN with a D8-Q200. Thats a 2.5hr sector on a 37seat prop, that said, the charterers are very happy with it!