Welsh Conservative Leader Darren Millar has raised concerns about the rising school absence rates in Conwy and Denbighshire.
Since the pandemic, unauthorised absences in secondary schools have nearly doubled compared to five years ago.
Local data shows a 150% percent increase in Conwy and a 116% increase in Denbighshire.
Mr. Millar has urged the local councils to urgently improve school attendance and support affected pupils.
He said: “These figures are deeply concerning and, clearly, urgent action is needed.
“Too many young people are missing out on large parts of their education, and I am particularly concerned about the long-term impact this will have on their futures.
“Wales already ranks lowest in education standards across the UK, and this is unlikely to improve when so many children are absent from school.
“I have written to Conwy and Denbighshire councils to highlight my concerns and to request information on what action is being taken to address this issue.”