Bovis claims it was hampered by numerous design alterations and a demand by SMPs that the building be increased in size. A confidentiality clause in its contract preventing Bovis from responding to the allegations was removed by the Scottish Parliament this week, allowing the company to put forward its version of events.
Bovis revealed to Building how much the project had been altered since its inception. The scheme's main contractor claims that floor space increased from 11,000m2 at concept stage to 18,000m2 at the end of the first year and will be 33,000m2 when the project is completed.
The views echo the opinion of ex-project manager Bill Armstrong who claimed that the parliament's decision to double the size of the building was partly to blame for the dramatic price escalation.
There has been a mass of design changes that Bovis has had to contend with. There have been 5000 variations in the six months leading up to May. Last month a 40-page report was also published detailing outstanding design issues. Extra terror-proofing has added more delays and an extra £28m cost to project costs.
Bovis, QS Davis, Langdon & Everest and joint architect RMJM were lambasted by Scottish MSPs last week for the latest £37m increase in project costs, which now stand at £375m. They agreed to have their fees capped for the rest of the project.
Many in the construction industry think that the Holyrood project team have been scapegoated by politicians. They say that SMPs should have been more realistic about the cost, and should not have kept changing the brief.
It may be political point scoring, but some politicians have started making synpathetic noises on behalf of the project team. Pete Wishart, SNP whip at Westminster blames the national Labour party, saying it was responsible for decisions over Holyrood including the choice of site, the design, and the open-ended contractual arrangements.
It also emerged that in the minutes of a meeting in March between the project team and the Parliament's Holyrood progress group D,L&E partner Hugh Fisher warned SMPs that the latest cost overruns were likely. Some SNPs wondered aloud whether the decision not to publicise Fisher's warning was connected to impending local elections.
Politicians currently in charge of the project have been on the back foot in the last week. Robert Brown, one of the SMPs on the parliament's corporate body announced that the project was likely to slip by another month. Last week November had been pencilled in as a completion date, but now Brown says it will probably be December or January before the building is handed over to SMPs.
This would mean that the parliament building wouldn't be up and running until next summer. This could have further implications for the building's cost. Another month's delay will push the final cost towards £400m and lead to more negative headlines in the Scottish press for the project team.
The taxpayer will have a better idea as to who is to blame when Lord Fraser reports the findings in his inquiry into Holyrood next year. Only then will we find out whether the builders or the politicians should take the blame for Scotland's answer to the Millennium Dome.