Well the strong winds today are forecast to be even stronger tomorrow afternoon - in excess of 50 knots at three thousand feet, and 30 knots on the ground, so more of the same.
Of course if the flow is perceived to be too severe the airlines are jumping all over NATS asking why its low - even if the weather situation is pretty obvious!
Airlines need to make up their mind what they actually want - an on-time off blocks departure (good for the punctuality stats eh?) and significant air holding; or a more punitive slot but less air holding. Make your minds up time.