In the wake of reports that Tesla has long known about weaknesses in its suspension componentry, U.S. Senators Richard Blumenthal and Edward J. Markey have sent a letter to CEO Elon Musk, calling on the company to recall the parts “swiftly.”

In their letter, the senators ask Musk to correct “apparent false and misleading representations” made to the National Highway Traffic Safety Administration (NHTSA) regarding the parts. They add they are “disturbed” that the company would blame its customers for weaknesses that internal documents show Tesla knew about.

“We write with extreme concern following recent reporting about Tesla’s knowledge of safety flaws in its vehicles and concealment of the causes of these flaws from the [NHTSA],” the senators wrote in the letter seen by Reuters. It cites an “alarming” investigation recently published by the same organization.

Read: Scathing Report Says Tesla Knew About Flawed Suspension Yet Blamed Customers

 U.S. Senators Call On Tesla To Recall Allegedly Faulty Suspension Components

Internal documents discovered by the outlet found that Tesla has known for years that components in its vehicles’ suspension, steering, and axles were prone to early failure. To reduce the costs associated with fixing these parts through its warranty program, Tesla reportedly told its mechanics to blame failures on customers.

Not only do the documents suggest that Tesla told service agents to blame breaking parts on driver abuse, but it also told NHTSA the same thing. The safety organization came to the automaker with concerns after Tesla was forced to recall certain suspension components in China — a decision it has said it disagreed with.

However, following the discovery of internal documents and engineering analyses that have found that certain safety critical parts are prone to fail in a matter of months, the issue has been reignited.

“We are disturbed that you would blame your customers for these failures,” Blumenthal and Markey wrote in their letter. “It is unacceptable that Tesla would not only attempt to shift the responsibility for the substandard quality of its vehicles to the people purchasing them, but also make that same flawed argument to NHTSA.”

The regulator is in the middle of an investigation into the fore links in Tesla Models S and X. Meanwhile, regulators in Sweden and Norway are also looking into the quality of Tesla’s suspension parts in certain vehicles, which could also lead to a recall.

 U.S. Senators Call On Tesla To Recall Allegedly Faulty Suspension Components