It would appear that the Labour MP for Newport West, Paul Flynn is concerned and worried. Apparently there is now a "consensus expert view" that the flooding of Gwent and Somerset in 1607 was caused by a tsunami and so he wants the British coast authorities to be provided with a tsunami watch early warning system.
No one seems to agree with him yet though. I imagine there's "consensus expert view" on many things that present theroetical horrors, although I'm not quite sure how we would easily monitor for a tsunami generated from the middle of the Atlantic.
My guess is the seismic activity across such a large expanse would end up causing multiple false alarms and people would start finding themselves unable to get insurance or sell their homes because of some thing with very low probability happening.
Still, at least Paul Flynn cares about his constitutents enough to spend some of their money by tabling a motion!