A ruling in the case against New Caledonia's mainly Kanak USTKE union over violence amid last month's strike is expected on June the 29th.
On Tuesday, the court heard the case against more than two dozen unionists, including their leader, Gerard Jodar, who were accused of impeding air traffic during last month's clashes at Noumea's domestic airport.
The prosecution wants Mr Jodar to be jailed for 15 months while the defence had tried to have the case thrown out.
The 12-hour court appearance drew union supporters to the court premises, with police imposing tight security around the building
Elsewhere in Noumea, several hundred people marched to denounce the union for the inconvenience it had caused.
Last month, a strike at the domestic carrier Air Caledonie was accompanied by a union attempt to seize the city's domestic airport which left domestic aviation for several days in disarray.