France kicked off Bastille Day celebrations on Monday in a whirlwind of controversy as Syrian President Bashar al-Assad joined dozens of leaders to watch the Champs Elysees military parade.

United Nations Secretary General Ban Ki-moon was the guest of honour at this year's festivities and two units of UN blue helmets were to lead off the traditional march from the Arc de Triomphe down to Place de la Concorde.

But President Nicolas Sarkozy's invitation to Assad has angered opposition politicians and some in the French military who served in a UN peace force in Lebanon, where Syria for years was the main power broker.

Making a diplomatic comeback after years of ostracism, Assad was among the more than 40 leaders who on Sunday inaugurated the new Mediterranean union, Sarkozy's flagship project to bolster cooperation between Europe, the Middle East and north Africa.

A group of French veterans accuse Syria of being behind a 1983 bomb attack on a Beirut building that killed 58 French soldiers and said Assad was not deserving of an invitation to France's national fete.

French soldiers should not file past the Syrian leader during the march down the Champs Elysees, said Jean-Luc Hemar, head of the Association of Veterans from Camp Idron in central France.

"We feel uneasy about this," he said, especially since some of the soldiers graduated from a military academy named in honour of one of the victims of the Drakkar bombing.

"Drakkar will cast a shadow over the 14th of July," he said.

Opposition Socialist leader Francois Hollande said Bastille Day festivities were being "tainted by controversy" over Assad's presence for celebrations marking the storming of the Bastille in 1789 at the start of the French Revolution.

The French presidency on Sunday defended the decision to invite Assad and said the 1983 truck-bombing of the Drakkar building in Beirut was carried out by the Iranian-backed Hezbollah and not Syria.

"To blame Syria for Drakkar is a historical mistake," said the Elysee official. "There's really no reason for such controversy."

France's left-wing Foreign Minister Bernard Kouchner last month commented that he was "not particularly pleased" by Assad's presence at the national fete.

Former president Jacques Chirac, who cut off high-level ties with Assad over the 2005 assassination of former Lebanese premier Rafiq Hariri, who was a close personal friend will be conspicuous by his absence from the dais.

Officials have denied that Chirac's decision to stay away was linked to Assad.

Sarkozy was leading his second national day festivities since taking office in May last year, with some 4,000 soldiers and more than 60 aircraft set to take part in a colourful parade starting off at the Arc de Triomphe.

After watching a fly-past of Alphajets, Sarkozy and invited guests including freed Colombian hostage Ingrid Betancourt were to view the march, with seven paratroopers set to wrap up the parade with a jump on the Place de la Concorde.

But the military display comes amid some tensions between commander-in-chief Sarkozy and the armed forces over plans to slash more than 50,000 defence jobs and shut down dozens of bases.

A group of senior officers last month openly criticised Sarkozy's new defence strategy that calls for reducing the size of the armed force to allow for massive investment in state-of-the-art intelligence technology.

The officers who called themselves "Surcouf" wrote in a newspaper commentary that France's military stature would be reduced to "the same league as Italy", bolstering Britain's defence role in Europe.