Daniel Ricciardo’s move from Red Bull to Renault has been one of the most dramatic stories which has emerged from the 2018 Formula One season.

Ricciardo will leave Red Bull at the conclusion of the 2018 campaign after five successful years competing for them, picking up seven grand prix victories along the way.

An increased salary is often a driving factor for drivers to change constructors and initially, that seemed the most likely reason why Ricciardo agreed on terms with Renault, with his new contract of $35million-a-year thought to more than three times more than his current Red Bull deal.

However, it turns out there might have been another factor which has influenced Ricciardo’s shock move to Renault more so than financial reasons.

Red Bull boss, Christian Horner has claimed that the 29-year-old has left Red Bull to take more responsibility as a senior driver.

This has emerged from Ricciardo’s frustration with Red Bull’s somewhat preferential treatment of Dutch teammate Max Verstappen.

This is despite Ricciardo being fifth in the current drivers’ championship with 118 points compared to Verstappen’s 105 points one place further back.

"He’s chosen to join the Renault team he feels are in the ascendancy. He knows the Renault product very well from all the time he’s spent with us," Horner said on the Beyond The Grid podcast.

"And I can’t help but feel he wants to be a leading role perhaps in a smaller environment.

"The competition between he and Max is intense. Max is growing stronger and stronger and I think that Daniel just decided that the timing is right for him to check out and try something else.

"Daniel said he decided after a long flight to America that he decided he wanted a change, now you look at the rational reason for that and it’s difficult to understand.

"I think it comes back to wanting to take on a new challenge, but I also feel that he sees Max growing and growing.

"In terms of speed and strength and he doesn’t want to play a support role, not that they are in any way treated different."

Horner claims that Red Bull ‘bent over backwards’ to not lose Ricciardo and they even offered a one-year deal to give him flexibility if Mercedes or Ferrari had been interested in 2020.

Instead, Ricciardo has decided to join Renault, a team with just 82 points in the constructors’ championship, without any podium finishes so far this season and a best result of finishing fifth in Azerbaijan and Germany.

How much the impending move affects Ricciardo's form for the rest of 2018 remains to be seen.