If you arrive by airplane you have to go into quarantine for two weeks on arrival meaning for a two week holiday you have to take a month off work.
BUT
The exception is the Eurotunnel which from today coupled with France relaxing lockdown rules is open for business meaning prices of holidays to France just went through the roof
Or you could drive to Paris via Eurotunnel and fly anywhere in Europe to go on holiday to bypass the quarantine
No health checks on arrivals by Train either by the look of it