Bernard Hogan-Howe indicated that he believed the current punishment of three penalty points and a £60 fine was not a strong enough deterrent for drivers.
By increasing the punishment to six points, drivers would be banned from the road if they were caught twice for the offence within three years.
Writing on the Met's website, the commissioner said this would make drivers take the law on driving while on the phone more seriously and improve road safety.
Asked during a live webchat by a cycling enthusiast why so many people still seemed to be getting away with using mobile phones behind the wheel, Mr Hogan-Howe replied: "Many people do not get away with it and get a fine and three points on their license.
"I would like to see them receive six points in the future. That would mean a second offence would lead to them being banned and I believe this would change driving behaviour and improve safety."
The commissioner's comments follow concerns that an increasing number of drivers are flouting the ban on mobile phone use behind the wheel despite tougher measures being introduced five years ago.
A study earlier this year suggested that around 200,000 motorists are fined for the offence in Britain every year.
More than 171,000 fixed penalty notices for using a hand - held mobile phone in a vehicle were issued in the 12 months up to last October, making it the fifth most common traffic crime, according to police figures. That is a rise of more than 4,000 on the previous record number, set in 2006.
Studies have suggested that driving while on the phone could be more dangerous that drink-driving.
Brake, the road safety charity, welcomed Mr Hogan-Howe's suggestion but said it does not go far enough in deterring drivers from using a phone behind the wheel.
Ellen Booth, Brake's senior campaigns officer, said: "This is encouraging, but we feel that those caught using a mobile phone while driving should receive an immediate 12-month disqualification, like those caught drinking driving.
"Research has shown that using a phone while driving leads to an elevated crash risk similar to drink driving, so the punishment should be the same too."
Mike Penning, the Road Safety Minister, said: "The vast majority of drivers know that they should not use a mobile while driving. To ensure that the penalty for using a mobile at the wheel acts as an effective deterrent to drivers, we are increasing the fine for the offence from £60 to between £80 and £100 later this year."
Motorists are permitted to use a phone's speaker or hands-free kit to avoid breaking the law as long as they do not hold the phone at any point, however police can still issue a £60 fine and three points if they deem the driver not to be in control of the vehicle.