"The staff member's response was that 'if the concept that marriage should be between a man and a woman is offensive, then I despair for the future of this country'. We agree."
Council communications and marketing manager Graham McKerracher said the council did not control the filtering process, which was done by a United States company.
When the company was employed, the council gave it broad categories of offensive content it wanted limited in its internal network.
The company's filter automatically scanned sites for words or phrases that placed sites in those categories and sites deemed offensive were automatically blocked.
Mr McKerracher could last night not say why the Protect Marriage site was blocked.
But a block meant the site, or someone leaving a comment on the site, might have used language determined by the filter to be offensive, resulting in the site being put on a banned list.
Mr McCoskrie said comments could not be left on the site and he was confident none of the administrators or owners of the site had previously done anything that could be construed as offensive or "hate" related.
Council staff were still able to access gay marriage websites, and at least two other websites blacklisted by web filters at other companies were able to be accessed by council workers.
"It is highly hypocritical and inconsistent that one side of the debate can be blocked, but not the other. This is discrimination at its worst and [the council] seems to be initiating their own version of hate speech laws."
Mr McKerracher said if sites promoting gay marriage had not been picked up by the same filter it was because no offending words or phrases that placed them in a category that was blocked were identified.
He said any staff member who wanted to fill out the petition could do so at home.