Sen. Richard Blumenthal, above, and Sen. Edward Markey sent a letter to Transportation Secretary Anthony Foxx asking him to issue a "park-it-now" order for the 2.6 million vehicles recalled by GM.

Senators Richard Blumenthal and Edward Markey continue to beat the drum to force General Motors to ask owners of the 2.6 million small cars it recalled to stop driving them immediately.

Blumenthal (D-Conn.) and Markey (D-Mass.) jointly penned a letter asking Transportation Secretary Anthony Foxx to force the automaker to make history and issue a “park-it-now advisory.”

“Every day that unrepaired vehicles remain on the road increases the risk of more injuries, deaths, and damage,” the pair wrote.

GM is now shipping the replacements for the faulty ignition switches in the vehicles that officially have been tied to 31 injuries and 13 deaths; however, it’s not likely that dealers will have enough replacements to fix all the vehicles until this fall.

U.S. District Judge Nelva Gonzales Ramos denied a lawsuit filed in Texas asking her to order GM to park the cars, saying she didn’t have the authority to issue such an edict. But she did write in her opinion about the ruling that the National Highway Transportation Safety Administration (NHTSA) would be the body that could issue it.

Despite her opinion in the ruling, it is unclear whether NHTSA can issue such a command. Until now, it’s never been done. For its part, GM maintains the vehicles are safe provided the drivers use only the key in the ignition.

“We believe you – as the federal regulator referred to by the court – have a unique opportunity to protect public safety by taking stronger action to issue warnings of these dangers,” Markey and Blumenthal implored.

(Toyota confirms plans to move to Texas. For more, Click Here.)

Apparently, the letter was received.

“We will respond directly to Senators Markey and Blumenthal regarding their letter,” the Transportation Department said in a statement. “In the meantime, we continue to urge owners and drivers of affected Chevy Cobalt and Saturn Ion vehicles to always wear their seat belts and until the vehicle is remedied, to follow GM’s recommendation to use only the ignition key with nothing else on the key ring when operating the vehicle. Owners can also contact GM for information on how to request courtesy transportation.”

(Click Here to read more about Oldsmobile’s history.)

During the recent Senate subcommittee hearings, Blumenthal and Markey attempted to pressure GM’s CEO, Mary Barra, to agree that the cars were unsafe and should not be driven. Barra held to the company’s policy that the vehicles are safe and she would let her son drive one, provided he followed GM’s guidelines for driving them.

(To see more about the UAW getting a seat on GM’s board of directors, Click Here.)

GM has handed out more than 30,000 loaner cars to owners who felt unsafe in their vehicles and is spending an estimated $1 million daily for those vehicles.