The legal battle (AJ 13.01.05) is over work carried out on a PFI education project the two firms completed last year in Brighton.
The practice is determined to force the firm to pay up for the work it carried out on the £20.7 million contract to extend and refurbish four schools for Brighton and Hove City Council.
Aedas' move comes as the culmination of a long-running campaign to win back the cash owed, that first saw it first take the case to adjudication.
The project saw extensive work carried out to Stringer High School, Patcham High School, Surrenden School and East Brighton College of Media Arts.
A spokesman for the council said that it had been happy with the work carried out.