Punishments for speeding drivers are about to get tougher under new sentencing guidelines for magistrates.

Motorists who commit the most serious speeding offences will face larger financial penalties from April 24.

Fines for drivers caught going well above the speed limit will start from 150 per cent of their weekly income rather than the existing level of 100 per cent.

For example, someone who is sentenced for driving at 101mph or faster in a 70mph zone will now be dealt with in a more severe bracket.

The Sentencing Council said the move aims to ensure there is a "clear increase in penalty as the seriousness of offending increases".

It follows responses to a consultation arguing previous guidelines did not properly take into account the increase in potential harm that can result as speed above the limit rises.

RAC road safety spokesman Pete Williams welcomed the change.

He said: "Anyone who breaks the limit excessively is a danger to every other road user and is unnecessarily putting lives at risk.

"Hopefully, hitting these offenders harder in the pocket will make them think twice before doing it again in the future.

"While greater sentences for excessive speeders are obviously a deterrent, the best deterrent of all is more effective enforcement."

Louise Ellman, chairwoman of the Commons transport committee, welcomed the change too.

"However, for enforcement to be successful, there must be the likelihood that offenders will be caught and prosecuted," she said, adding a declining number of dedicated road traffic police officers is of "real concern".

Justice minister Sam Gyimah said: "Speeding can have tragic consequences, so there must be strong penalties in place to deter drivers from behaving recklessly.

"These new guidelines will help make sure sentences properly reflect the seriousness of the crime."

Neil Greig, director of policy and research at road safety charity IAM RoadSmart, cautiously backed the guidelines as being welcomed by the majority of law-abiding drivers.

But he added: "The effect they will have on those already willing to flout the law and put themselves and others in danger remains to be seen."