The U.S. Department of Transportation rejected two democratic senators' request to advise owners of 2.6 million recalled GM cars to stop driving until repairs.

General Motors, one of the biggest global car makers, continues to fight legal battles involving its recent recall of 2.6 million small cars across the world. The widely reported issue with the cars' ignition switch, which has proven lethal in some cases, is taking a new turn as the secretary of the U.S. Department of Transportation rebuffed two democratic senators' request to stop owners of affected cars from driving until a permanent remedy is applied.

 General Motors recall involving 2.6 million small cars, mainly Chevrolet Cobalts and Saturn Ions, has been a controversial topic for the automaker. The company is shipping replacement parts to the dealers so the problem with the ignition switches is fixed permanently. The switch abruptly turns off the car's engine and knocks out power-assisted steering, that can cause drivers to lose control and crash. The safety airbags also gets disabled, which puts driver's life at further risk.

GM said the ignition switch fault has resulted in 13 deaths and admitted knowing the problem for over a decade. But it took action just this year. The car maker has suggested that drivers not use key chains as the added weight causes the switch to malfunction. But a permanent fix is needed, which is expected by October.

Concerned with the elevated risk of damage with the recalled cars, two Democratic senators, Edward Markey of Massachusetts and Richard Blumenthal of Connecticut, wrote a letter asking the government to order owners of affected cars to park their cars until GM fixed the problem.

"NHTSA is satisfied that for now, until the permanent remedy is applied, the safety risk posed by the defect in affected vehicles is sufficiently mitigated," Anthony Foxx, U.S. Transportation Secretary, wrote in his letter, according to Bloomberg.

But Markey and Blumenthal disagreed with Foxx's move and said the government and the car maker are not taking enough action to prevent further damage. "We remain extremely concerned that GM and NHTSA are not doing enough to convey the seriousness of this defect to owners of the affected cars, unnecessarily putting more lives at risk," Bloomberg quoted Markey and Blumenthal as saying in a joint statement, Thursday. "Secretary Foxx has raised more questions than he has answered."