Flybe right now are having a bit of a tough time and their competitors will likely be very much aware of this.
What stops the likes of Easyjet and Ryanair from deploying A320 / B737 aircraft on Flybe's main trunk routes ? I'm thinking of the likes of SOU-EDI/GLA/MAN/JER/AMS and the equivalent out if EXT, BHX and MAN ? Easyjet have not been afraid to make life harder for Flybe on the Isle of Man
As relatively short routes, runway length becomes less important. The only thing I can think of is competition law (I can't really see MOL worrying that aggressive competition would not look very nice to the middle classes !) but as long as LCCs can show they were not price dumping they would presumably have a defence in court