Franz Tost has hit back at criticisms over so-called Formula 1 B-team models and feels his team’s success comes from a collection of stronger elements rather than purely purchased parts.

Renault chief Cyril Abiteboul has been a vocal opponent to the B-team model, particularly with focus on the 2021 F1 rules shake-up, as he believes it discredits the input and effort from factory efforts who manufacturer all its car parts and engine.

Currently F1 teams can purchase non-listed parts from other teams – which is a practice currently used by Toro Rosso from Red Bull and Haas from Ferrari – but from 2021 the listed parts looks set to expand to curtail smaller teams relying on manufacturers and ensure more is produced in-house.

While the rules can’t be substantially changed until 2021, Tost sent a barbed comment back by saying “he simply hasn’t done his homework” and defended his team model.

“If someone who runs a manufacturer team is complaining that the small teams are faster and better than him, then he simply hasn’t done his homework in a proper way,” Tost said. “We at a Toro Rosso, we have from Red Bull Racing the gearbox from last year, the rear suspension from last year and parts from the front suspension – most of the front suspension we’ve anyway done ourselves.

“So, the reason why Toro Rosso is so competitive is mainly because of the fantastic power unit which we have from Honda.

“It seems that others are not doing such a good job and therefore they should not complain and whingeing around. They just should do their job.

“We have a good package together with the car, fantastic drivers and a fantastic power unit from Honda, that’s the reason why we are competitive.”

Haas team principal Guenther Steiner has backed up Tost’s comments in Bahrain and says as long as the rules permit the current team structures there should be no complaints from rival manufacturers.

“As Franz says, leave us alone, leave us doing our job. We are fine, get back to yourselves,” Steiner said. “I think a lot of these manufacturer teams should also see the opportunities they are given because they want to take something away from us, I see it like this, which was there before.

“We didn’t invent it. Red Bull, Toro Rosso, Haas, Ferrari didn’t invent this. This was there, we took it, this model and they did. If they want to do it they can do it but we are not going to say you have to do it, so we are not the people which want to take something away from the manufacturers.

“If you think your way is the better one, have it like that. Good luck and I wish them well, but if you don’t deliver as Franz says, if you are yourself your own problem, because you don’t do it well, don’t blame other people doing a different job for doing it well and trying to diminish what they are doing by making it worse, because in doing that, the gap will grow.

“At the moment the teams which have these affiliations with the big teams, they are getting closer to the top three and that’s what it should be.”