Toro Rosso is Red Bull's junior team, and this year is using many parts from its sister squad, including the rear end and the front suspension.
Abiteboul questioned how it has been able to show strong pace over winter testing despite not having a technical director for much of 2018 following the departure of James Key, who will soon take on duties at McLaren.
"Just look at Toro Rosso, who in my opinion are likely to be the team to beat as far as we’re concerned for the start of the season given where we are,” said Abiteboul.
“Toro Rosso had no technical director for most of last season. It’s very clear what went on. So we don’t even need a technical director to produce what is a very competitive car. For us that’s a problem.”
Abiteboul has warned F1 that if it doesn't take measures to avoid encouraging B-team situations, no new manufacturers will join the grid in the coming years.
"There was a before and after Haas that has created a precedent. I’m not challenging, but I’m just saying how do we move forward for teams like us, like McLaren, like Williams?
“But also how does a manufacturer that’s currently not in Formula 1 that wants to join Formula 1, how is it they will seriously contemplate reaching Formula 1 if it’s not possible to win without a B-team?
“For me that’s a strategic question we have to consider for the discussion for 2021. For ’19 and ’20 that’s gone now, we are gone with that type of set-up. But for 2021 I hope everyone realises how serious a question it is.”