The Monaco Grand Prix stewards have criticised the GP2 field following Thursday's qualifying session that was heavily disrupted.
The 30-minute session was marred by incidents caused by drivers backing up towards the end of the lap to create some clear space ahead of them. Several drivers had multiple hot laps ruined as they encountered cars queuing up through the Swimming Pool, La Rascasse and Anthony Noghes corners.
The disruption also led to several collisions. The stewards have accepted that backing up should be acceptable to some level on the tight streets of the Principality, but they have hit out at the drivers for taking it too far.
A statement from the stewards said: "One is accustomed at Monaco to competitors slowing at Rascasse in order to create space between themselves and the preceding competitor.
"What is not expected is that competitors should slow not only as Rascasse but as far back as the entry to the Swimming Pool, such that a competitor endeavouring to set a time is confronted with a queue of much slower competitors for a considerable part of the lap.
"The stewards consider this practice as unacceptable, potentially dangerous, and it is this that has contributed to an unnecessarily problematical qualifying session which did not do justice to the GP2 Series."
The officials also explained that the penalties handed out to Giedo van der Garde, Marcus Ericsson and Romain Grosjean for causing collisions were reduced to five places on the grid instead of 10 because the drivers they hit had to shoulder some responsibility.
"Penalties have been issued in respect of three drivers each of whom collided with the rear of other competitors whilst endeavouring to set a qualifying time," the statement said.
"The penalties so applied are of a lesser degree than those normally applied for the offence of causing a collision.
"The reason for this is that the stewards consider other competitors must also share some of the responsibility."