The poster advertises the Fonthill Vase. The 14th-century ceramic, it declares, is on display in the National Museum at Collins Barracks, Dublin. In fact, this great international treasure is in storage. There are plenty of other empty glass cases in the new National Museum.

When the technical and professional staff of the museum, members of the IMPACT union, downed tools two weeks ago because of a dispute over staffing levels, they left a lot of work unfinished.

A floral tapestry is conspicuous by its absence. Daniel O'Connell's repeal cap is nowhere to be seen. A linen damask tablecloth associated with the Liberator's stay in the Bridewell languishes in storage.

There are other problems. Some vital information notices are either missing or not fixed properly to the objects on display. Many cases are empty or else filled with still-wrapped artefacts. Silver chalices rest on cardboard boxes and packing material.

Some glitches, like the medieval carved statue of St Molaise leaning very slightly in its case, are barely noticeable; others, such as the glaring space where a reed raft should be, are unmistakable.

What visitors to Collins Barracks will find is a nearly complete array of costumes, weaponry, furniture, silver and ceramics. For those who have put years of their life into the exhibition, nearly is just not good enough.

"The public are being hoodwinked," says Anne O'Dowd, a curator with the Irish folk life section of the museum. "The advertisements give the impression of a first-class museum but the place is clearly not finished.

"We were forced to down tools because of a dispute that could have been sorted out. The museum should never have been opened to the public."

The reason the curators withdrew their services is the management structure of the museum. It is unchanged since 1928 and, according to the curators, is in dire need of an overhaul.

Over the years, two independent reports by international museum consultants have recommended additional staffing and restructuring. Some employees have been on the same point on the salary scale since 1962.

And so it transpired that at the grand opening of the National Museum last Friday, a day many of the more senior technical staff had waited a lifetime to see, they were picketing outside the building with nothing to celebrate. To their experienced eyes the exhibition as it stood was incomplete.

According to Mr Noel Delany, head of museum services, the decision to go ahead with the high-profile publicity campaign and the opening of the museum was made between the museum management, its caretaker board and the Department of Arts, Heritage, Gaeltacht and the Islands.

"It wasn't an easy decision to make and the public will decide for themselves, but there is still an awful lot to see," he said. "We have had a uniformly positive response from the public and those people visiting from international museums."

Indeed, in its first week of opening 7,000 visitors filed through Collins Barracks, and 500 last Sunday alone. But, says assistant keeper Ms Colleen Dube, the public is getting a raw deal.

"As far as I am concerned Collins Barracks represents a notional museum, not a national one," she says. "At the end of the day it is the public who suffer. They are not getting the exhibition they deserve."

Dr Raghnaill O Floinn, a curator in the antiquities section and spokesman for the National Museum branch of IMPACT, described the situation as "heartbreaking".

"This dispute has been going on for a year. The authorities have had more than enough time," he said.

"None of the workers are happy about this. Their work has taken over their lives for the past three years."

Mr Paul Doyle, curator of the period furniture section, says he is concerned that the public is not aware that what is on view is an incomplete exhibition.

"That is why we are leafletting the public. Basically the exhibition lacks the finishing touches that turn the ordinary into the extraordinary," he said.

For Mr Michael Kenny, a curator of the silver section and an employee of the museum for more than 20 years, the most disheartening aspect is that he did not get to complete the detailed information panels.

"Most of the objects are in place but the information panels which explain the nature of the different pieces are missing in a lot of cases. It is still a wonderful collection of silver but from a punter's point of view the answers to the crucial why, when, who, where questions are not available," he said.

A spokesman for the Department said the Minister was working "assiduously" to find a solution to the problem.

"While we accept that it is not finished there is still sufficient material there to provide a very enjoyable exhibition for the visitors who are already visiting in great numbers," said the spokesman.

It is estimated that a resolution of the dispute would cost the Department £20,000 a year. The opening celebrations are understood to have cost more than £150,000. Two thousand invitations were sent out, less than half of which were accepted because of the dispute. The Taoiseach refused to pass the picket line.

A source inside the museum blamed "Civil Service wrangling" for the impasse.

"It is not about money. The mandarins in the Department of Finance are worried that if they accede to the demands it will open the floodgates to other claims," he said.

Meanwhile the posters continue to advertise a vase that is not there. After The Irish Times pointed out that this was slightly misleading, the museum announced that henceforth the poster would not be used until the vase is on display.

"I only joined the museum three years ago and I was astounded that a project this big was undertaken with very little strategic planning," said Ms Dube. "What astounds me is that people don't see the potential of a national museum.

"I heard a member of the caretaker board saying that even though it was unfinished the exhibition would give people a `flavour' of what a national museum means. Well, I for one am not in the business of making an Oxo cube out of Collins Barracks."