Remember that movie in which Bill Murray was trapped in an endlessly looping nightmare?
As those of you who've watched Groundhog Day will know, the experience of witnessing an urbane and cynical weatherman repeating a single day in a wintry Pennsylvanian Hicktown – Scrooge crossed with the flying Dutchman – was highly amusing. The construction industry's version of this morality tale is the Scottish parliament, and that isn't so funny. Take Brian Stewart, for example. The chief executive of architect RMJM broke down in tears last week when he told the Fraser inquiry into Holyrood about the day in 2000 when he heard the news of Enric Miralles' brain tumour. He described the project as a "nightmare" and, understandably, said he would not take part in any future parliament buildings. Presumably Stewart and other witnesses – there have been about 50 called to the stand so far – are hoping that some semblance of normal life will return after completion.

The cycle of variation, delay, cost overrun, media outrage and public outrage has now taken a new twist. Nigel Griffiths, the part-time construction minister, has put the out-turn cost for the parliament at £500m – a whopping £70m over the last estimate (see news). Although Griffiths admits this is a "guestimate" recent history suggests the Edinburgh South MP may not be far from the ultimate truth. Doubts were also expressed last weekend that the construction team will meet the summer completion deadline. The saga continues … and continues.

Watching Stewart under the spotlight, and observing his genuine distress, begs a question that has yet to have been voiced north of the border – why are we holding the Fraser inquiry now? Has anyone bothered to question the logic of running the inquiry while the project crawls to completion? Is grilling project team members, who no doubt have had to spend considerable time preparing their evidence, on live television for days on end really the best way to make sure that the project hits its summer deadline?

It is right and proper for Holyrood's huge cost increases on a public to be scrutinised. Yet for first minister Jack McConnell to have called the inquiry more than a year before the job has been completed is just one more cock-up to add to the list. Lord Fraser himself acknowledges the risk in a foreword on the inquiry's website but he adds that he expects "all involved in the Holyrood project from the early planning stages to the completion of the building to co-operate with the inquiry team".

In the foreword, Fraser also expresses his wish "not be rushed", and he assures us that "we will get it right" in his conclusion. It's a pity, then, that his probe is doing nothing to give the project team a chance to get it right. Fraser's proceedings seem only to have succeeded in further lengthening the nightmare.