I take your point to a certain degree. This morning between 6am and 7am Tui had six departures. Jet2 had the same between those times....yet Jet2 had zero take offs between those hours and all of Tui's left. Now that ain't ATC issues on Jet2's behalf!
indeed Karl, its not always just related to ATC delays, maybe Jet2 also have a shortage of ground crew, or even checking in staff on Sunday, or could it be connected with re-fuelling, maybe swissport get priority over the fuel tankers before Jet2? - Most likely a combination of everything!