As the Department for Transport announced plans to fine drivers for an array of minor motoring offences, statistics show that the number of police on motorways has fallen by nearly 23 percent, meaning that it could be harder to impose the new measures when they come into force next month.

The plans include issuing three points on a licence and a £100 fine for offences such as tailgating, cutting up other drivers and poor lane discipline, which includes overuse of the middle lane on motorways.

Figures provided by Damian Green, a home minister show that traffic police officers had fallen from 6,299 in 2007/8 to 4,868 in 2011/12, meaning that it may be difficult to enforce the new measures on motorways and trunk roads where middle lane hogging is an issue.

In the rules of the Highway Code, motorists should fall back into the left hand lane traffic when not overtaking traffic, though many motorists do not do this, meaning more drivers have to use the right hand lane for overtaking.

This information has given motoring groups doubts over the new curbs, including Kevin Delaney of the Institute of Advanced Motorists who said: “All the discussions we have been having about this are hypothetical because there aren’t any police to enforce them. There is no real definition of tailgating or hogging the middle lane. In theory it’s a good idea, but the devil is in the detail.”

A spokesperson for the Department of Transport defended the new proposals saying: “These charges are being introduced following extensive consultation with police forces. It is for individual police forces to decide how they allocate their resources between policing roads and other areas.”