Aaren Russell’s rookie Supercars Championship campaign is in serious jeopardy following a tumultuous weekend at the Castrol Edge Townsville 400.

The future of Russell’s entry was one of the biggest talking points of the event after a trackside dispute between Erebus Motorsport owner Betty Klimenko and the CEO of sponsor Plus Fitness, John Fuller on Saturday.

A disagreement over promotional activities being undertaken by the sponsor in the paddock triggered a last minute deal for Plus Fitness to also appear on the two Lucas Dumbrell Motorsport Holdens.

The bizarre turn of events came amid an already fractured relationship between the Russell camp and Erebus after a trying first half of the championship that sees the driver languishing in last of the full-time runners.

Amid its off-season move from Queensland to Melbourne and switch of manufacturers, Erebus had been on the brink of fielding just a single entry before cutting a deal with the Dunlop Series stalwart.

The agreement saw Russell bring the Plus Fitness sponsorship and a second ex-Walkinshaw Holden to Erebus, paying the team to run the car under its #4 Racing Entitlements Contract.

The cost of upgrading the Russell car to keep pace with the team’s main entry and a need to source more sponsorship for the clearly vacant bonnet are understood to be among the key issues.

Aaren’s father Wayne Russell, who put the deal together for his son to graduate to the main series, declined to comment on the immediate future of the entry when approached by Speedcafe.com this week.

Fuller meanwhile stressed his company’s continued support of the Russells, which it had backed in the Dunlop Series prior to the move into the main game.

“We’re still 100 percent behind the Russells,” Fuller told Speedcafe.com, downplaying the importance of his own friction with Erebus at the weekend.

“They’ve got to decide where they are moving forward with Erebus and whatever decision they make moving forward we’ll support.

“We have a separate commercial arrangement with Erebus for car #9 (minor sponsorship) that is also still in place.”

Compelled to field two cars for the full year under the REC rules, Erebus will have to find a replacement driver for the Ipswich event in just over a week’s time if issues with the Russells cannot be resolved.

Erebus is understood to have guaranteed access to the second Holden chassis for the remainder of the season regardless of Russell’s future, while it also has its fleet of Mercedes-AMGs should a back-up car be required.

Erebus general manager Barry Ryan told Speedcafe.com that the team hopes to continue with the Russells at Ipswich, but admits that the deal is far from guaranteed to continue.

“We’ve got a bit to decipher,” Ryan told Speedcafe.com.

“We’ve signed the REC agreement so we will be running two cars regardless, hopefully exactly how it has been running.

“That’s what everyone wants to happen, we’ve just got to agree on a few things to make sure it does.”

Erebus enjoyed its most encouraging weekend of the season to date in Townsville with its driver David Reynolds, who qualified fifth and ran in the top three for much of Sunday’s race.

Engineer Ryan was, however, left to rue the decision not to pit under the final yellow after those restarting on new tyres behind demoted Reynolds to an eventual 14th.