The Supreme Court decision on whether parents can be prosecuted over term-time holidays is expected to be announced on Thursday morning.
Jon Platt, the Isle of Wight dad whose legal challenge led to the landmark case, announced on his Facebook page that the judgement is expected at about 9.45am.
The businessman, who has said he is not confident about the outcome, ended his post: "Keep your fingers crossed for me."
Platt won a case in 2015 against Isle of Wight council over a fine for taking his daughter out of school for a week, a decision that was upheld by the High Court.
But the Isle of Wight council and the Department of Education appealed to the Supreme Court and the case was heard earlier this year.
The Platt case centred around the fact his daughter had a good attendance record for the rest of the year.
After the Supreme Court hearing, Platt said he was not confident the judges would rule in his favour.
He repeated his fears this weekend, in a interview with The Sunday Times, where he said he was sure he would lose.
If so, he has said he will take his daughter out of state school and into private education, where the fines do not apply.
