Yes, but hang on HSL.
CAP371 says
1.3 A crew member shall not fly, and an operator shall not require him to fly if either has a reason to believe that he is suffering, or is likely to sufferer while flying from such fatigue as may endanger the safety of the aircraft or of its occupants.
2.2 Planned schedules must allow for flights to be completed within the maximum permitted flying duty period. The authority when assessing the planning of a schedule will take into account the time allowed for pre-flight duties, taxying, the flight and turnround times.
If you are going 2.5 hrs into discretion the CAA must know about it. If you are going regularly into the 2 hrs tell the CAA about it. The SRG does have a web site.
What I cannot understand is how your night Tenerife is going into discretion unless it departs after 2159. Prior to that time you have 11.15 hrs duty and a Tenerife out of the middle of the UK should take about 8.45. Add 2hrs to that for checkin and turnround which allows 30 mins slack. Loose that with the delay and you still have to do a 3 hr turnround in TFS to go 2hrs into discretion.
At the end of the day, If you cannot comply with either CAP 371 1.3 & 2.2 don't do it.