The whole Dublin set-up has to be an issue impacting growth at some significant U.K. airports - most notably Manchester.
Pre-clearance facilities are a nice thing to talk about, but they’re not all that! And the more flights using DUB over the Atlantic the less appealing and less beneficial the whole pre-clearance set up gets. It simply moves the bottleneck to the east side of the Atlantic.
The bigger issue is the ludicrous level of U.K. Air Tax, with the ostriches down at Treasury in London murdering the regional aviation industry in the U.K. - even Double taxing U.K. domestic flights - and herding passengers in the direction of Dublin, Amsterdam etc. Then history shows that when other economies overheat, notably Ireland a few years back, the self-same sages under the direction of No 11 write out a big fat cheque from the hard-earned U.K. coffers to keep those who have faltered trucking along in the manner to which they have become accustomed!
Why not, for instance, multiply air tax on traffic being diverted out of the U.K. regions over other EU airports in order to help offset a tax break to the industry - both domestic and international - at airports inside the U.K.?
Oops sorry - that would require a thought wave to drift north of the Watford Gap. Silly Me! ....