A trio of organizations that sued the Georgia Public Service Commission early this year after it approved billions more in spending for two new nuclear reactors at Georgia Power Co.’s Plant Vogtle, were in court Wednesday asking a judge to intercede.

Estimates for the cost for the troubled project, already billions of dollars over budget, have ballooned from $6.1 billion to $10.3 billion—an amount the PSC deemed “reasonable” in an order entered a few days before Christmas last year in what the plaintiffs say was a rushed, illegal vote.