The operator will launch Menorca, Malaga, Alicante, Reus, Zakynthos, Fuerteventura and Gran Canaria from 25 July.
It will also resume operations at Bristol airport the same day.
By August 1, Tui will operate to 24 destinations from 12 UK airports – Birmingham, Bournemouth, Bristol, Cardiff, Doncaster, East Midlands, Exeter, Gatwick, Glasgow, Manchester, Newcastle and Stansted.
Tui’s Covid cover, meanwhile, will be included for all passengers travelling on Tui holidays between 11 July and 31 December 2020 and applies to all new and existing bookings.
The cover includes overseas Covid testing for suspected cases, overseas medical assistance if a customer contracts Covid on holiday, costs associated with an extended stay and a new return flight home if customers must self-isolate on holiday, and access to a dedicated 24/7 emergency hotline and app.
Tui says the cover should be used in conjunction with travel insurance, and should not be considered a replacement for travel insurance.
Andrew Flintham, TUI UK and Ireland managing director, said: “Many of our customers have been waiting with eager anticipation to hear about whether they could go on holiday this summer, so we’re delighted our first customers will depart this weekend.
"We’ve done a lot of work to ensure we can take our customers on relaxing, enjoyable and - most importantly – safe holidays again and it’s really exciting to be able to offer our customers additional peace of mind when booking with us, with our new Covid-19 cover.
"It means that they can book with confidence, knowing that extra costs associated with COVID-19 that wouldn’t be covered by regular travel insurance, will be taken care of."
Flintham said Tui would expand its operations "as more of the world starts to open up to tourists. "We want to be there to take those who want to travel away to enjoy some summer sunshine, so we’re adding more of our most popular destinations for holidaymakers to choose from.
“Of course, as this is such a fluid situation, we understand the need to be flexible, and may need to adapt and modify our plans as we go along. If we do need to cancel more holidays in line with government advice, all affected customers will be able to receive a full refund.
“Our Tui Holiday Promise still stands, so our customers can rest assured that if we think they can’t enjoy their Tui holiday as they intended, we won’t take them there.
“We know some people may not feel confident travelling right now, but we’re inviting them to start looking forward to holidays again, and we can’t wait to take them away whenever they choose to join us.”