The case of a father who refused to pay a £120 fine for taking his daughter on an unauthorised term-time holiday is due to be heard by the High Court.
Magistrates had ruled that Jon Platt had no case to answer as, overall, his daughter had attended school regularly.
But Isle of Wight Council has asked the High Court to clarify whether a seven-day absence amounts to a child failing to attend regularly.
Campaigners say the case could redefine the way the law is applied in England, the BBC reported.
Stricter government regulations since 2013 have meant head teachers can only grant leave of absence to pupils during term-time in “exceptional circumstances”.
Platt took his daughter to Disney World in Florida in April 2015.
Her school on the Isle of Wight had refused permission for the trip but he took her anyway and she missed seven days of lessons.
Platt was issued with a £60 fixed penalty fine. After he missed the payment deadline, the council doubled the fine to £120 which he also refused to pay.
Isle of Wight Council then prosecuted him for failing to ensure that his daughter attended school regularly.
Platt successfully argued there was no case to answer as the prosecution had failed to show that the child did not attend regularly.
Even with this and other absences, he maintains her attendance remained above 90%, the threshold for persistent truancy defined by the Department for Education.
Magistrates heard that the girl had also been removed from school earlier in the year for an unauthorised holiday by her mother, from whom Platt is divorced, so her attendance record for the year was only just above 90%.
However, the February absence was not part of the council’s case against Platt.
Platt argued at the magistrates court that it was not a crime to remove a child from school for a holiday.
The question was whether the child had failed to attend regularly and the act does not define “regularly”.
The magistrates asked the High Court: “Did we err in law in taking into account attendance outside of the offence dates… as particularised in the summons when determining the percentage attendance of the child?”
Platt has crowdfunded £25,000 to cover legal costs.
Craig Langman, chairman of the Parents Want a Say campaign against the term-time holiday ban in England, called the court case “a pivotal moment”.
“We are backing Jon Platt all the way. It’s time we bring discretion and common sense back into the education system. This nonsense has been going on for two years too long,” he was reported as saying.