The case, which could well decide the movement's future in France, is the first since the adoption there last year of tough anti-cult legislation that allows the dissolution of suspected sects found guilty of common offences.

Prosecutors will charge the Church's inner temple, the Spiritual Association of the Church of Scientology in the Paris region, and its president, Marc Walter, with abuse of civil liberties, misleading publicity and attempted fraud.

"It's a hugely important case, the first time the Church has been accused as a legal entity in its own right," said Olivier Morice, a lawyer for the National Union for the Defence of Families and Individuals, which is demanding that the organisation be outlawed.

The case stems from the complaints of three men, including two former Scientologists, who were sent brochures, booklets and invitations from the Church two or three times a week for several years despite having repeatedly demanded to be removed from its mailing lists.

A year-long inquiry headed by Judge Renaud van Ruymbeke found that the three men's names featured in half a dozen different Scientology databases maintained in France and Britain but also at the organisation's European HQ in Denmark and the International Association of Scientologists in Los Angeles.

"That is a clear-cut case of breach of civil liberties and data protection legislation," a spokesman at the public prosecutor's office said yesterday. "The judge also argues that the organisation was set up specifically to commit these offences."

The Church, which has dismissed the case as "a minor affair about the complaint of a couple of individuals", will also be accused of attempted fraud based on the "false allegations and untrue promises" in its tracts.

Unlike the US, France refuses to recognise Scientology as a religion, arguing that it is a purely commercial operation out to make as much money as it can at the expense of often vulnerable victims.

In a trial in Marseille three years ago, five Scientology officials were found guilty of selling bogus "purification" treatments costing between £1,200 and £15,000 but consisting mainly of sessions in the sauna, jogging and vitamin pills.

Other leading French Scientologists have in the past been sentenced to jail terms - often suspended - for fraud and other financial offences, but this is the first time the Church itself and its recruitment methods have gone on trial.

Founded in 1954 by the late L Ron Hubbard, an American science fiction writer, the Church of Scientology claims more than 8m members worldwide, including the Hollywood stars Tom Cruise and John Travolta.

In France, where the organisation says it has some 50,000 members, Scientology was first described as a sect in a 1996 parliamentary report, and still features on a list of 173 groups under permanent government surveillance.

The movement was again strongly criticised this week in the government's annual report on quasi-religious activity. It accused the Scientologists of trying to "cash in on catastrophe", handing out thousands of pamphlets offering help and advice after last September's explosion at a chemical factory in Toulouse that killed 30 people, injured 2,500, and left 1,400 families homeless.

Last year France became the first country to pass specific legislation against sects, creating a new offence, the "fraudulent abuse of a state of ignorance or weakness", which carries a prison sentence of up to three years and a maximum fine of £250,000.

The Church of Scientology has described it as "an attempt to impose state atheism".