Telegraph also has this:
Coronavirus quarantine: All UK arrivals 'will have to self-isolate for 14 days'
Travellers will be required to fill in a digital form and declare the address where they will be staying with hefty fines for breaches
All visitors to Britain will be ordered to isolate for 14 days in a bid to prevent a second wave of coronavirus, Boris Johnson is set to announce on Sunday.
Travellers arriving in the UK will be required to fill in a digital form and declare an address where they will then be expected to self-isolate for 14 days, as revealed by The Telegraph.
Visitors could face fines of up to £1,000 and even deportation if spot checks later find they have flouted the rules, which the report claimed could be introduce in June.
https://www.telegraph.co.uk/news/2020/05/09/uk-arrivals-will-have-self-isolate-14-days/
Further openness and levelling with the public, this was a briefing. Not a public statement.
Six occurrences of "will" - followed by the undermining use of "could". That gives us confidence.
If it is such a good idea (and I am broadly in agreement with the measure):
Why was it not done months ago?
Why do we have to wait until June?
A fine of £1000 is inadequate. It needs to be vastly more significant to the wealthy. Like at least the possibility of being taken directly to a magistrates court and detained. And a fine proportionate to their assets.
Also in Guardian:
The idea of a quarantine has been mooted for some time, and transport secretary Grant Shapps has hinted at such a measure once the infection rate within the country is under control so the government is sure that the illness is not being imported.
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However, questions will be raised as to why this measure was not introduced sooner, and what the scientific reasoning is for it to be introduced at this point in the government’s response. Other countries, including Australia and New Zealand, ordered 14-day isolation periods for visitors as early as March.
https://www.theguardian.com/world/2020/may/09/two-week-coronavirus-quarantine-to-be-announced-for-uk-arrivals
Clearly, if a satisfactory test for infectiousness were available, that could limit the period required.