TAP Air Portugal is currently offering an attractive £1250 business class return fare to Rio de Janeiro from London or Manchester.
This is valid for travel from very late January 2020 until the end of the current booking period. It isn’t available every day, but it is on most days.
The headline fare on the TAP website is £1,360. This is reduced to £1,250 if you use code TAP10FLY3006 until 30th June. Here is a screenshot:
From Lisbon, you will be changing to a new Airbus A330neo with the latest TAP business class seat.
Your best option to maximise your miles when paying is American Express Preferred Rewards Gold. This offers double points – 2 per £1 – when you when you book flight tickets directly with an airline.