The 26-year-old first signed for the British outfit - then Team Sky - in 2017.

He has enjoyed his best season including his first stage win at February's Herald Sun Tour in Australia.

Doull's fresh contract agreement comes as he rides his first Grand Tour at the Vuelta a Espana.

"Here at the Vuelta, I've spoken to a lot of the riders and staff and everyone says that after your first Grand Tour you can physically move on quite a lot," said Doull.

"I understand the Vuelta is a good Grand Tour to do first too, because it sets you up well for your off-season, so hopefully I am starting from a higher level next season and that progression will carry on into the Classics."

Doull, who finished second at Kuurne-Brussels-Kuurne in March, is again targeting early season one-day success and hopes to emulate fellow Welsh Team Ineos rider Luke Rowe.

"2020 will be similar to last year with a big focus on the Classics before switching to that support role in the big stage races," said Doull, whose team-mates also include Tour de France winners Geraint Thomas and Chris Froome.

"It's a role that Luke Rowe has performed so well for years and he is someone I massively look up to.

"Progression is probably the key word for me - I want to carry on learning from the best people in the best team in the world."