Synlait's boss says the company's facing its toughest period in 20 years, but hopes a turnaround is near. 

The Canterbury milk processor's posted a half year loss of $80.6 million. 

Revenue rose $32 million to $949 million, while debt soared 88$ to $472 million. 

Chief Executive Richard Wyeth told Mike Hosking the next six months are critical. 

He says they've got the sale of a North Island asset coming up but need to catch up on a backlog for advanced nutrition, then they can focus forward. 

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