By Thomas Escritt

THE HAGUE (Reuters) - A relaxed-looking former Ivory Coast president Laurent Gbagbo appeared in the International Criminal Court on Tuesday to hear whether accusations of crimes against humanity against him are strong enough for a full trial.

Gbagbo, accused of plunging his country into civil war after 2010 elections rather than relinquishing his grip on power, would be the first ex-head of state to be tried by the Court, whose credibility is at stake after a string of collapsed cases.

His lawyers accuse the Hague-based tribunal of doing the bidding of his successor, Alassane Ouattara, who has since sought to kickstart the economy of the world's top cocoa grower and the country that was once the commercial hub of West Africa.

The 67-year-old former history professor, who was dressed in a sobre business suit and whose face was expressionless as he watched proceedings from his seat at the back of the court, is not due to speak until late next week. The sessions have been spread over several days to take account of his frail health.

Some 300 or so supporters of Gbagbo gathered on a patch of grass opposite the court to demand his release. "He's not a dictator," said one supporter who called himself Babadwe.

"Gbagbo loves his people and his people love him. Have you ever heard of a president who kills his people and then have his people love him?"

The hearing is crucial for the Court's own prosecutors, who will seek to convince judges that Gbagbo has a case to answer after a string of high-profile failures.

They must prove that Gbagbo ordered his forces to commit murders, rapes and other human rights during violence in which some 3,000 people died in a four-month civil war that uprooted a million people from their homes.

Late last year Congolese warlord Mathieu Ngudjolo Chui was acquitted in the court's second ever verdict, and prosecutors have failed to make charges stick against four other African suspects.

RECONCILIATION EFFORTS

Gbagbo says he was leading government resistance against what he describes as Ouattara's foreign-backed northern rebellion. Ouattara saw himself as the champion of excluded northerners who suffered under Gbagbo's southern government.

The conflict came to an end only after Gbagbo was arrested by forces loyal to Ouattara, with the help of French troops, prompting Gbagbo's supporters to argue that he is the victim of post-colonial meddling.

Prosecutors have also issued an arrest warrant for Gbagbo's wife Simone, but Ivory Coast has not surrendered her to the ICC's custody.

A close Gbagbo ally, the leader of the Young Patriots youth movement Charles Ble Goude, was arrested last month in Ghana and was immediately extradited to face trial in Ivory Coast.

Gbagbo supporters and human rights groups have complained that abuses carry out by pro-Ouattara forces during the conflict have yet to be punished, arguing that this is holding back efforts to reconcile southerners and northerners.

Many Ivorians want to draw a line over the whole conflict.

"I think that the youth need to understand that Gbagbo has had his day and it's over now," said Norbert Toualy, a pensioner in the commercial capital Abidjan. "He can come back after his trial, but he's no longer going to be president."

(Additional reporting by Ange Aboa in Abidjan and Mark John in the Hague; editing by Mark John)