HALIFAX -- The restoration of the Bluenose II hit another snag Wednesday after a much-anticipated test drive was called off a couple of hours before it was due to begin.

The Nova Scotia government issued a news release the day before, saying the schooner would conduct engine, steering and anchor tests in Lunenburg harbour if the weather co-operated.

The Department of Communities, Culture and Heritage had also lined up its deputy minister, Kelliann Dean, to address the media in Lunenburg following the vessel's return.

But on the morning of the test drive, the province issued a brief statement saying it was missing a certificate from the American Bureau of Shipping that would allow the vessel to leave the dock.

"The Bluenose II pre-sea trial has been postponed until further notice," read the three-sentence release posted online.

No new date has been set.

Glenn Friel, a spokesman for the Department of Communities, Culture and Heritage, could not say why the government didn't have the certificate in time for the test. He said more information would be available later in the day.

The Bluenose II has been undergoing a multi-year restoration that's been plagued by budget overruns and repeated delays, the latest caused by a problem with the vessel's steering system.

The government said May 1 that a test drive would have to be completed before sea trials take place -- the final phase of the project.

The Opposition Progressive Conservatives blamed "Liberal incompetence" for the last-minute cancellation, saying the latest glitch was inexcusable.

"The Liberals had 28 days to make sure they were prepared for this test drive, yet here they are cancelling it at the eleventh hour," Tory critic Karla MacFarlane said in a news release.

"The Liberals must immediately explain how this happened and when the boat will actually sail."

Communities, Culture and Heritage Minister Tony Ince said last month that the project's cost had ballooned to nearly $18 million.

Still, Ince said he was optimistic the vessel would be seaworthy for at least a portion of the tourism season.

The iconic schooner was supposed to return to regular sailing in the summer of 2012 after an extensive two-year rebuild at a cost of $15.9 million, with $4.9 million from Ottawa. Since then, Nova Scotians have seen proposed dates for sea trials and official launches come and go.

The Bluenose II, launched in 1963, is a replica of the original Bluenose, a Grand Banks fishing schooner that won worldwide acclaim for its graceful lines and speed.

In January, Premier Stephen McNeil asked the province's auditor general to review the restoration that began under the previous NDP government, calling the project a "boondoggle."