A pressure group, which campaigns against "established state religion", has told a High Court judge that a council was acting "unlawfully" by including the saying of prayers on meeting agendas.
The National Secular Society (NSS) challenged the "practice of holding religious prayers" during meetings of the town council in Bideford, Devon, in what could be a test case.
Society officials argue that the religious ritual is "inappropriate" in what should be "a secular environment concerned with civic business".
David Wolfe, for the society, told Mr Justice Ouseley on Friday that prayers were an issue because they were part of the council's "formal agenda".
"The claimants challenge the town council's practice of holding religious prayers," Mr Wolfe told the court. "It is only an issue because they are part of the formal agenda."
He added: "We say the conduct of holding prayers within the formal part of the meeting is an unlawful practice."