14 Day Quarantine is essentially enforceable and works in lock-step with Travel Advice, as the UK Government also applies its FCO Travel guidance advising UK Nationals against Non Essential Travel to the same country. eg Spain, Portugal.

Thank you, Paul Charles for providing the transparency which should have come from the Government long ago.

this is a complete dogs dinner - simplest option is to stop all travel

No.
The simplest option is for the government to bother to make their promised 'world beating app' for track and trace. Another failing of this appalling government.