By Tim Luard BBC News Online

About 4,000 pro-China supporters staged a march through the capital, Taipei, on Sunday to show support for the island's official name, the Republic of China.

Pro-China supporters do not want the island's name changed

At a much larger demonstration the previous day, about 50,000 independence activists had demanded that the name be formally changed to Taiwan.

What may look like a squabble over something as superficial as a name is in fact a significant new manifestation of a major identity crisis that has dominated Taiwan's politics for more than 50 years and continues to threaten the island's security from attack by China.

Beijing regards Taiwan as a breakaway province that must be reunified with the motherland - if necessary by force. A name change would be seen as a seriously provocative step towards independence.

Saturday's rally was led by a man reviled by the Chinese Communists - Taiwan's former president, Lee Teng-hui - and organised by an alliance of some 70 pro-independence groups.

It was one of Taiwan's biggest political demonstrations in years.

Former Taiwan president Lee Teng-hui has infuriated China

But a report from Taipei by China's official Xinhua News Agency on Sunday made no mention of it. Instead, the agency said that "tens of thousands" of people had spontaneously taken to the streets on Sunday in what it called a "gigantic" patriotic demonstration against independence.

What's in a name?

Once known in the West as Formosa, the island is today known as Taiwan by almost everyone. But its formal name is a source of endless confusion and diplomatic wrangling.

"Republic of China" is a legacy from the era when Chiang Kai-shek's nationalists ruled the mainland. Chiang kept the name when he and his supporters fled to Taiwan in 1949 after losing the civil war.

The victorious communists renamed the world's most populous nation "People's Republic of China", which is now recognised by the United Nations and the vast majority of countries.

Taiwan - home to 23 million people - has become increasingly isolated in world affairs and has been forced by Beijing into using names such as Chinese Taipei in those few international bodies it has succeeded in joining.

Many want Taiwan recognised as an independent country

Its domestic politics are also split between the descendants of Chiang's nationalists, who favour eventual reunification, and indigenous Taiwanese, who are more inclined towards independence.

Mr Lee told demonstrators on Saturday it would be easier to gain diplomatic recognition by formally adopting the name Taiwan than by retaining the Republic of China title. It was now time for the Taiwanese to exercise self-determination, he said.

Passports changed

The current president, Chen Shui-bian, from the Democratic Progressive Party, has given the name change his qualified support.

In a symbolic gesture that infuriated Beijing, his government approved the use of the name "Taiwan" on islanders' passports from last week.

But Mr Chen - with one eye on presidential elections next March, when he is expected to seek another four-year term - stayed away from Saturday's march. He did say, though, that if he had not been president, he would have gone along - with his grandson.

He is keen to avoid alienating mainstream voters, most of whom support the status quo.

This is an international joke. Lian Chan, Nationalist Party chairman

The president's likely opponent at the elections, the Nationalist party chairman Lien Chan, condemned him anyway, saying he should concentrate on economic problems instead of worrying about Taiwan's name.

"At a time when people cannot have three square meals a day, when many have been jobless for long periods, our government marches on the streets asking for Taiwan's name to be rectified," said Lien. "This is an international joke."

Both sides of the political spectrum know that far from being a joke, the issue of Taiwan's identity has a habit of overtaking daily economic concerns and dominating the island's big elections. The poll in six months' time looks like being no exception.

But the government is unlikely to want to make too much of the proposed name change for the moment, with most people in Taiwan anxious that nothing be done that would needlessly upset an increasingly rich and well-armed China.

Sunday's smaller, anti-independence march included many elderly veterans of the civil war and several descendants of Chiang Kai-shek, all of whom stressed the need to maintain friendly links with their former communist enemies.

The relative youthfulness of those who attended Saturday's rally suggests the pro-independence camp has time on its side... unless, of course, China should decide to invade first.