Police forces in Britain penalised almost 6,000 motorists for the offence in the four weeks after tougher punishments took effect, equivalent to one every seven minutes.
The figure includes 324 offences recorded in Yorkshire and the Humber, with almost half of those in West Yorkshire.
Campaigners claimed the “worrying” findings suggest many drivers are ignoring repeated warnings about the dangers of using phones at the wheel despite a string of publicity campaigns and the risk of harsher sanctions.
From March 1, those who fall foul of the rules have faced receiving six points on their licence and a £200 fine – up from the previous three points and £100.
The changes mean new drivers risk losing their licence for sending a single text.
Calls for efforts to curb illegal mobile phone use intensified in the wake of a string of high-profile cases and research indicating that it is widespread.
Figures obtained following Freedom of Information requests show forces recorded 5,977 instances of the practice in the four weeks after the clampdown was rolled out alongside a nationwide police campaign.
The actual figure is likely to be higher as seven forces did not provide figures and some cases may not have been logged at the time responses were issued.
The Metropolitan Police registered the highest number at 2,037, followed by Thames Valley Police at 478 and followed by Police Scotland at 339.
West Yorkshire Police, the largest force in Yorkshire, recorded a total of 140 such offences.
There were 72 in South Yorkshire, 52 in North Yorkshire and 51 in Humberside, meaning each of the four regional forces caught the equivalent of one driver using their phone illegally every day.
The RAC Foundation described the increased penalties as “a start”, but warned the figures for March suggest “the key message still isn’t sinking in”.
Steve Gooding, director of the motoring research charity, added: “Hands need to be on the wheel and eyes looking out of the windscreen, not down at the phone screen.”
The figures have sparked calls today for more investment in traffic policing to compliment the tougher penalties.
There have been falls in the numbers fines for using handheld mobiles in recent years amid reductions in full-time dedicated roads policing officers.
Jack Kushner, spokesman for Huddersfield-based charity Brake, described the number of drivers “selfishly using their mobile phones behind the wheel” as concerning.
“Driver distraction is a growing menace and it’s worrying that drivers don’t seem to be getting the message,” he said.
The charity wants the £200 fine to be “significantly increased” to deter offenders.
Department for Transport figures show 22 people were killed and 99 seriously injured in accidents on Britain’s roads in 2015 where a motorist using a mobile was a contributory factor.
Anthony Bangham, National Police Chiefs’ Council lead for roads policing, said forces were committed to tackling the behaviour and driver must understand it was not a minor offence.