What are the seven reasons or where can I find list, please?
This is from the legislation for public transport (in England). The shop legislation has not been published yet and will probably appear around 11:59pm next Thursday:
These Regulations require members of the public to wear face coverings whilst using public transport (such as buses, trains, the London Underground, trams, aircraft and water taxis) in England to protect against the risks to public health arising from coronavirus, except in certain limited cases.
www.legislation.gov.uk
I rather doubt if the CPS would pursue it.
So do I. Particularly if the "shops" SI follows that for public transport. That SI has been badly drafted. It says this:
"No person may, without reasonable excuse, use a public transport service without wearing a face covering."
This puts the onus on the prosecution to prove, beyond reasonable doubt, that the defendant had no reasonable excuse. It is notoriously difficult to prove a negative. The defendant is not required to explain what his reasonable excuse is at the time he was stopped and he is not required to explain it in court before the prosecution ends its case. The wording of the SI requires the prosecution to prove that he had no reasonable excuse and quite how they would do that without the defendant's co-operation is a little unclear.
The SI should have been drafted along the lines of S172 of the Road Traffic Act. This requires (very broadly) the Registered Keeper of a vehicle to provide the details of the driver at the time of an alleged offence (e.g. being "flashed" by a speed camera). It says (again very broadly):
"The person keeping the vehicle shall give such information as to the identity of the driver as he may be required to give by or on behalf of a chief officer of police."
There are no "ifs", no "buts". All the prosecution has to do to prove their case is to show, beyond reasonable doubt, that a notice was served and that no response was received. But the Act also goes on to say this:
"A person shall not be guilty of an offence ....above if he shows that he did not know and could not with reasonable diligence have ascertained who the driver of the vehicle was."
[my emphasis]
So, a get out clause (a "statutory defence"), but the burden is on the defendant to show he could not identify the driver, not on the prosecution to prove that he could. This could easily have been done with the face covering legislation, viz:
"It is an offence to travel on public transport without a face covering". Then "
but a person shall not be guilty of an offence if he shows that he had a reasonable excuse."
If S172 had been drafted in the same way as the face coverings SI there would never have been a successful prosecution for "failing to provide driver's details". Unless either the SI is modified or some case law from a higher court interprets it to mean that you have to prove you had a reasonable excuse when challenged I cannot see any convictions being recorded against those who simply choose to keep their "reasonable excuses" to themselves.