There was a 4 per cent increase in the number of deaths and serious injuries in the past 12 months, reaching almost 25,000, amid claims that technological “distractions” are causing motorists to lose concentration.

The data suggested that accidents were now on the rise after a long-term decline in injury rates over the previous three decades.

Incidents involving cyclists showed the biggest rise, with a record 3,500 deaths or serious injuries in the 12 months to last September, up by 8 per cent. Major accidents among children increased by 3 per cent to more than 2,000, representing the first year-on-year rise since the mid-1990s.

Officials suggested that the increase was driven by a rise in the number of cars taking to the road over the past 12 months.

The disclosure prompted claims that the government had become complacent about its road safety record, with cuts in funding for awareness campaigns.

The RAC said that many motorists were becoming distracted by the sheer number of gadgets installed on the dashboard of newly built cars. This included technology allowing motorists to connect smartphones directly to sound systems to make calls, play music and get directions.

Its own polling has shown that mobile phones are a “major source of distraction” for more than a quarter of drivers, rising to four in ten among those in their late teens and early twenties.

Pete Williams, the RAC’s head of external affairs, said: “Is it the case that many of us don’t link reaching for the phone with staying safe, and think we’re likely to get away with it?”

Julie Townsend, deputy chief executive of Brake, the road safety charity, said: “These casualty increases . . . come on the back of three years of flat-lining road death and serious injury figures, during which the government congratulated itself on having some of the safest roads in the world, rather than making forward thinking decisions.”

In all, 1,730 fatalities were recorded in the 12 months to September, a figure 1 per cent higher than the same period a year earlier. Some 24,360 people were killed and seriously injured and there were 192,910 casualties of all types, a 5 per cent increase. It was only the third time in 30 years that the number of accidents had increased after a downward trend in the number of deaths and injuries.

Robert Goodwill, the transport minister, said: “We are determined to do more to reduce these figures, working with the police and other agencies.”