No trip to Athens is complete without visiting the Acropolis, the glory of Ancient Greece perched on top of the craggy limestone rocks overlooking the "new" city.

The Acropolis was built in Athens' first Golden Age in the 5th century BC - an era of monumental public works and grand ideals. Today, with a touch of grandiosity, the Greeks say they are planning another Golden Age - bringing the ancient Greece of the Acropolis together with the modern, teeming Greece below. But there's tension between the two.

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On the one side you've got reform-minded, efficient Greece, the member of NATO and the EU and host of the Olympics, and its new roads, metro and airport; and on the other side you've got poor, parochial Greece, a Balkan backwater plagued by old disputes but rich in ritual and tradition and proud of its Ancient Heritage. And there's a row going on here which sums up this identity crisis: the row between the Orthodox Church and the Greek government.

When I tell you the row is over a couple of words on a flimsy piece of card, it may all sound rather petty. But thousands of people have taken to the streets over it and the topic is plastered all over the papers.

Those two little words are "Greek Orthodox" and they have until recently always been written on the identity cards which the Greeks are obliged to carry. But in a bid to protect the privacy and freedom of its citizens, the new Greek government has banned the inclusion of religious affiliation on any new cards, saying it doesn't fit in with its new multicultural stand.

Why all the fuss?

In Greece being Orthodox is a way of life. If you question the supremacy of Orthodoxy here you are questioning the centrality of the Church to Greek identity, culture and history. And with nearly one hundred per cent of native-born Greeks registered Orthodox you can understand the scale of the argument.

Father Matjeo Halaris has campaigned against the change

The Church is furious with the government. It has organized a petition against the government decision to remove religious affiliation from identity cards and to force a referendum on the issue. The Church says it has already collected 3 million signatures. One priest I met in Athens, Father Matjeos Halaris, had collected 6,000 signatures from his diocese of 10,000. His congregation said they were "protecting the truth".

The campaign is being led by the charismatic, assertive Archbishop of Greece, Christodolous. He calls this his "crusade".

Archbishop Christodolous is spearheading the Church's fight back

The Archbishop's spokesman, Haris Conidaris, told me that during the 400 year old occupation of Greece by the Turks - up until independence in 1821 - it was the Church which "kept up the language, the faith and the passion for liberty" among the people. He says the reason Archbishop Christodolous is so determined to fight his corner is "the effort of some government members to de-Christianize the country". This is a battle for the hearts and minds of the Greek people.

Justice Minister Michaelis Stathopolous wants reform of the ID cards

The man who has been speaking out on behalf of the government is the Justice Minister, Michaelis Stathopolous. I asked him whether the government could really ignore 3 million Greeks - maybe more; maybe, as some church leaders are claiming, half the Greek population.

"We don't know exactly how many signatures there are," he answered, "but let's say there are 2 - 3 million signatures. Well there are 8 - 9 million people registered Orthodox so that means the greater number have not voted. It is the Church that has managed to divide the Greek Orthodox people, not the government."

Strong passions - and deeply-rooted beliefs

Wherever I went people had strong views on the issue. Even if they supported the government they were often angry that it had made its decision without consulting them. And very few people denounce the church outright. But Public Sceptic Number One in Greece, the writer and journalist, Nikos Dimou, was less restrained.

Commentator Nikos Dimou: too much 'wishful thinking' about the Church in Greece?

"We Greeks, " he told me, "build false truths around ourselves in order to be able to project our wishful thinking on society". He continued, "The reality of the Church being the guardian of the Greek people during the Turkish Occupation is simply a myth. The Church was the extension of the Ottoman Empire. This is the first time the government is really opposing the church because up to now it has always backed down."

For the new Euro-friendly Greek government, this is essentially an issue of personal and private choice. International human rights groups have been complaining for years over Greece's lack of tolerance of minorities and of other religions.

Nikiforos Diamandouros: it's a matter of citizens' rights

Nikiforos Diamandouros, Greece's first Citizens' Rights Ombudsman, explained why they were taking such a firm stand: Greece has a large immigrant population who are not Orthodox and they must not feel discriminated against. "Until the late 1980s Greece had been one of the most homogeneous countries in Europe. That has been reversed. Since the end of the Soviet Union, borders have opened and large numbers of people are coming in. Now ten per cent of the population are not Greek natives ... (and) the law demands equal treatment of all citizens, irrespective of their religion."

Also in this edition of Crossing Continents:a chat with the notorious Mimi Papandreou, once the first lady of Greek politics.