It has been reported today that the FCO has updated it’s travel advice to UK citizens meaning that river cruises and no fly cruises in or around the UK will now be permitted. This means that cruises recently put on sale by lines like Hurtigruten as soon as September would be allowed to operate as planned.
The advice remains slightly unclear with the FCO website advising those booked on a UK cruises to contact the Department for Transport, but the general consensus from the industry is that this updated advice permits no fly UK cruising from today effectively.
https://www.gov.uk/guidance/cruise-ship-travel