PREMIER Barry O'Farrell personally intervened to head off an inquiry into the Orica chemical leak by begging the minor parties to block it.

His office staff are also under pressure to explain why they failed to tell the Premier of the environmental disaster immediately after they received an alert.

Damning documents have been released in parliament after a call for papers by the Greens. Those documents reveal a paper trail of who in government knew of the spill from Orica's Kooragang Island plant near Newcastle.

The spill occurred on Monday, August 8, but hundreds of Stockton residents were not told until the Thursday night of the danger of being exposed to hexavalent chromium, which can cause cancer.

Mr O'Farrell has been caught out lobbying the Christian Democrats and Shooters parties to block the opposition's parliamentary inquiry into the leak.

Orica was willing to speak out

Emails show he personally contacted them on Monday, August 17, asking them for their support in blocking the inquiry.

Five days later, when he hadn't received a reply from the Christian Democrat's Fred Nile, he sent an email to his chief of staff, Peter McConnell, saying: "We need to ensure we don't have two inquiries going at the same time. Neither Christian Democrats MLCs responded to my email - it would be worth getting Dunc (Roads Minister Duncan Gay) or Mike (Police Minister Michael Gallacher) to follow up so we avoid the same problem."

An independent inquiry is being held by former premier and cabinet department's director-general Brendan O'Reilly who is due to report back at the end of this month.

No cancer risk from Orica leak

Originally published as Kill Orica inquiry, independents asked