Hundreds of Hounslow parents have been threatened with fines this year for failing to keep their children in class.
Hounslow Council took on new powers to punish the parents of persistent truants a year ago.
No families have actually been hit by the £50 fines so far but 415 parents of bunking youngsters have been handed warning letters, the final step before fines are enforced.
A council spokesman said: "Fixed penalty notices are one of the measures available to us to ensure children attend school on a regular and punctual basis, so they are able to take full advantage of every opportunity on offer to them to succeed.
"Our policy is to initially use them for repeated unauthorised term time leave absences, only after warning letters have been issued.
"So far we have not had to take action beyond this, but we are monitoring the attendance of the children of the 415 parents who have received the warning letters."
The vast majority of the truants are from the Hounslow, Cranford and Heston areas, where 229 warning letters have been sent.
A further 136 parents are being monitored in Chiswick, Brentford and Isleworth but only 50 regular truants were identified in the Feltham, Bedfont and Hanworth areas.
The fines are one of a number of council measures which can be used to deal with unauthorised absences but it is police who regularly deal with truants found on the borough's streets.
PC Phil Beale has been a member of the Safer Schools team in Isleworth and Brentford and Chiswick for three years.
He said: "Lots of kids will try skipping school at some time but are usually caught quite quickly. We're talking about a very small percentage of kids who truant regularly and have to be picked up and taken back to school."
PC Beale says his colleagues have a good knowledge of the children in their area with low school attendance and can generally find them quite quickly once notified by the school.
"We know where they'll be and they know us," he added. "There'll always be a small number of persistent truants but we have become very effective at scooping them up and getting them back into classes."