Pastor Maldonado fears Williams have taken a massive step backwards after failing to progress through to Q2 in Melbourne.
After a dismal campaign in 2011, Williams made progress last season even securing a pole position and race victory in Spain.
However, in Melbourne this Saturday there were no signs of that improvement.
Driving the ]FW35 for the first time in qualifying, Maldonado only managed a 1:47.614, which meant he failed to make it through to Q2 in the rain.
"I think we're back to where we were two years ago, with the condition of the team," he told reporters.
"We need to work very hard to sort the problems. The car is undriveable at the moment.
"In the wet conditions we were slow and in the dry we were slow as well. The pace for tomorrow seems to be better for us but our qualifying pace was very bad."
His new team-mate Valtteri Bottas progressed after finishing 15th, three-tenths up on Maldonado.