Katherine Heigl has pledged to support behind-the-scenes workers in the entertainment industry

In a lengthy Instagram post, Katherine - who has Nancy, 12, Adalaide, nine, and Joshua, four, with singer Josh Kelley - explained: "I’ve celebrated life’s big and small milestones with my crews. First real love. Marriage. Babies. Turning 21. Turning 30. Turning 40. The crews I’ve worked with all these many many years have been just as instrumental in making me who I am as anything else lasting and important in my life. They have been family in that way and I have always and will always continue to support and stand by them. (sic)"

Katherine subsequently addressed the backlash she encountered more than a decade ago, after she decided to speak up on the issue.

Her post continued: "Some of you may remember over ten years ago I was very vocal about the absurdity of the working hours crews and actors were being forced into by production. Even Diane Sawyer interviewed me and not so kindly informed me 'no one feels sorry for you.' I very publicly and for many many years after got my a** kicked for speaking up.

"I let that public spanking shut me up and shut me down. I took a very big step back from the hustle of my career and retreated into the woods of Utah. I spent a fair amount of time struggling with self confidence and self worth. I let myself be convinced that I was wrong. Very very wrong. That speaking out made me seem ungrateful or precious or as if I were 'biting the hand that fed me.' (sic)"

Now, though, Katherine is determined to fight for justice and to speak her mind on the issue.

She wrote: "I speak up today and say with zero hesitation or regret…14, 16, 17, 18 hour work days are NOT safe. They are NOT healthy. They can not and should NO longer be tolerated. (sic)"