Stoffel Vandoorne believes McLaren has not made any progress in Formula 1 this season after admitting it is "difficult to get a worse weekend" than the Belgian Grand Prix.
Vandoorne came home last of the 15 finishers in his home F1 race at Spa, having qualified slowest on a weekend when he and team-mate Fernando Alonso both lacked pace from the opening practice session onwards.
McLaren's slump means it has scored points in only three of the last eight races, which has dropped it away from the Renault/Haas fight for fourth in constructors' championship and closer to Toro Rosso and the Honda engine it ditched for 2018.
Vandoorne said: "It's difficult to get a worse weekend. We've seen the performance we have is very far away from being good.
"There's not really an explanation.
"The reality is we haven't progressed since the start of the year, we haven't progressed at all compared to the others."
After multiple problems on Friday, Vandoorne had also urged McLaren to sort its reliability before trying to compare him to reserve Lando Norris - who is being assessed as a 2019 contender with GP practice runs.