(Reuters) -A group of Democratic Texas lawmakers has asked Tesla to delay its much-anticipated robotaxi launch in Austin until September, when a new autonomous-driving law is scheduled to take effect.

The group of Austin-area lawmakers said in the letter sent on Wednesday that delaying the launch, which CEO Elon Musk said could "tentatively" happen this Sunday, "is in the best interest of both public safety and building public trust in Tesla's operations."

If Tesla decides to move forward with a launch this month, the lawmakers asked that Tesla respond with "detailed information" demonstrating how Tesla will comply with the new state law when it launches.

Musk last year staked Tesla's future on autonomous-driving technology as it pivoted away from chasing rapid growth in electric-vehicle sales.

Tesla did not immediately respond to a request for comment on the letter.

It is unclear how much weight a letter from Democratic lawmakers will carry in a state where Republicans hold the governorship and majorities in both legislative chambers.

Musk announced in January that Tesla would be offering "autonomous ride-hailing for money in Austin, in June," and since then the Austin rollout has been closely watched by investors and analysts - many of whom attribute the majority of Tesla's stock market value to hopes for robotaxis and humanoid robots the company has yet to deliver.

Current Texas law allows autonomous-vehicle firms to operate their vehicles anywhere in Texas, as long as the vehicles meet basic registration and insurance requirements. The new legislation, which passed the Texas legislature last month and has not been signed by the governor, would for the first time require autonomous-vehicle companies to apply for authorization to operate in the state.

It would give state authorities the power to revoke permits if they deem a driverless vehicle "endangers the public." Firms are also required to provide the state information on how police and first responders can deal with the vehicles in emergency situations.

Musk and Tesla have given few details about their plans for the Austin robotaxi launch. The CEO has said the Austin rollout would begin with 10 or 20 Model Y vehicles, and that the company will begin operating in "only the parts of Austin that we consider to be the safest." Musk and Tesla have not said who the passengers will be, how Tesla will charge for rides, where in Austin they will operate or how extensive remote monitoring and operation of the vehicles will be.