Changes to the law proposed in Parliament yesterday could give the authorities the power to clamp down on private-hire car services such as Uber and Grab if their drivers are found to be operating without proper licences and insurance.

Under the Road Traffic (Amendment) Bill, a blackout period of up to a month can be imposed on these services, during which private-hire drivers will be prohibited from driving for the errant ride-hailing service. This essentially suspends its operations and ability to serve commuters.

Such a suspension order can be imposed if a private-hire car service has had three or more instances of drivers flouting the rules within a year. For instance, drivers who use unlicensed vehicles to conduct chauffeur services, operate without a valid vocational licence and do not have appropriate motor insurance.

A spokesman for the Land Transport Authority (LTA) said: "Frequent infringement of these rules poses potential safety risks for commuters and hence a suspension order may be necessary."

The suspension order for the car service will come on top of penalties imposed on the errant drivers.

A motorist operating an unlicensed public service vehicle, for example, can currently be fined up to $3,000 or jailed for up to six months.

The Bill will have to be read a second and third time before it is passed.

The proposed penalties dovetail with new regulations that will be imposed on the private-hire car industry by the first half of this year.

Under these regulations, private-hire drivers will be required to go through a vocational licensing course and undergo a background screening and medical check.

Cars being used for services such as Uber and Grab must also be registered with the LTA, and they must have decals identifying them as private-hire vehicles.

When asked about the latest proposed changes, Uber said it is "supportive of any effort by the Government to improve the well-being and safety of riders and drivers".

An Uber spokesman said the firm will study the implications of the proposed amendments.

A Grab spokesman said the firm has several checks in place to ensure its drivers are compliant, including a robust registration process and a vehicle inspection framework.

He added that these existing processes will help support the proposed amendments.

There are an estimated 25,000 cars being used for Uber and Grab.