The Government has been urged to rethink its decision to send a naval ship on a three-month trip to South and Central America later this year.
The trip will cost approximately €500,000.
Fine Gael says the trip cannot be justified at a time when 'a tsunami of drugs' is being illegally imported into this country and when the naval service is cutting coastal patrols by 200 days this year.
The Department of Defence says the 14,000-mile trip will have significant economic benefits and will not affect the level of patrolling on the Irish coast.
It said the voyage had been factored into this year's operational planning and would not result in the diminution of effective patrolling activity in Irish waters.
The LE Niamh is to visit Argentina, Chile, and Mexico to take part in ceremonies to mark the 200 anniversary of the overthrow of Spanish rule in the region.
It will also be used to promote Ireland as a business and tourist destination.
In a statement today the Dept of Defence defended the decision to send the LE Niamh to South America.