Monadelphous has lashed out at development groups over $33 million in cost blowouts for their FMG Pilbara pipeline job.
Monadelphous alleges the additional costs were incurred because of a late start to the project, which disrupted plans and pushed construction into the northern wet season.
Monadelphous also says contractual variations were requested by DDG.
Practical completion of the FMG pipeline took place in March 2015 rather than December 2014 as agreed in the contract.
It is also alleged that DDG did not provide adequate site access until November 2014, months after the agreed time.
The $183 million pipeline was commissioned to enable to FMG to lower costs by switching the TransAlta-operated Solomon power station from diesel to gas.
DDG has said it will vigorously defend its position in court.