New questions have been raised about the Welsh assembly's £67m Senedd home after another bout of problems with the building only weeks after it opened.
Contractrors said they were working to rectify the problem
Cracks have appeared for a second time in the oak desks used by AMs in the debating chamber. Last month, the building's roof sprung a leak.
Tory William Graham said AMs were told the desk faults had been fixed, so the new problems should not have happened.
The assembly government said they were "minor defects" which would be mended.
The desktop flaws - described by Mr Graham as "dramatic" - have appeared in a number of work stations used by AMs.
Similar cracks have appeared in woodwork in the public gallery of the Cardiff Bay building, which was opened by the Queen on St David's Day, 1 March.
Within days of its state opening, the landmark building, designed by Lord Richard Rogers, had to undergo repairs after the roof began leaking in heavy rain.
The problem with the desks is the second for contractors. The assembly's plenary session was delayed in January after inch-wide splits were among a number of faults they had to deal with.
Mr Graham, Tory representative on the assembly's house committee, said the problem of increased heat in the assembly chamber, a possible cause of the split wood in the work stations, should have been anticipated.
He said: "The committee were assured that these problems, once identified, had been solved. Now we find several weeks later that this is not the case.
The Senedd was officially opened by the Queen on 1 March
"If one is pessimistic, it will get worse, or very much worse when we have warmer weather.
"This building is meant to be so sophisticated that it shouldn't allow excessive heat build up, particularly when it was unoccupied.
Mr Graham said he feared ministers may have "rushed the project" and the Labour assembly goverment should bear the blame.
Maureen Kelly Owen, a past president of Royal Society of Architects in Wales, said the desks difficulty was typical of the "teething problems" any large, design-led building could expect.
She said: "You could build an unadventurous, cavity-wall building, totally unexciting and lacking in innovation, and you would get one that would never leak, and never move, but it would be so dead boring that architecture would never move on."
A Welsh Assembly Government spokesperson said: "Constructing a large-scale building will always bring up minor defects that need to be remedied.
"We are working with the contractor to resolve this matter and they will bear the cost of any remedial work as part of our fixed price contract."
A spokesperson for contractor Taylor Woodrow said: "We are aware of the problem and are working with the Welsh assembly to rectify it.
"The fitting out process began on schedule and was carried out within a pre-agreed timeframe."