THE contractor building the Perth to Mandurah railway line must do "whatever it takes" to get work restarted on the strife-plagued project, even if it means sacking striking workers and hiring others, the state opposition has said. As Alan Carpenter again told workers to get back to work or prepare to face the consequences, opposition industrial relations spokesman Troy Buswell said bringing in new workers as strikebreakers was one of the few viable options left for joint contractor Leighton Kumagai. Leighton Kumagai general manager Ray Sputore said last week the contractor would not sack the workers for breaching the terms of their employment.