A million Australian households will be the target of an automated phone poll on same-sex marriage conducted on behalf of conservative senator Cory Bernardi.

Key points: Cory Bernardi argues robocalls are not "invasive" compared to a text message

Cory Bernardi argues robocalls are not "invasive" compared to a text message The robocalls will feature the voice of Senator Bernardi expressing concern for same-sex marriage

The robocalls will feature the voice of Senator Bernardi expressing concern for same-sex marriage He says same-sex couples offended by the robocalls can simply hang up

The Australian Conservatives leader argues the robocalls are not "invasive" and will include his views against legalising same-sex marriage ahead of the close of the postal survey.

The poll will include a voice message from Senator Bernardi himself, expressing his concern about the effect of same-sex marriage on families.

"I've done the voiceover for this call so people recognise they're talking directly to an elected politician rather than going through some anonymous research company," Senator Bernardi said.

"I can speak for my concerns as a parent, I can speak for my concerns for the future of the country and the consequences of it.

"Doesn't mean other people have to enlist in it. But I'm really more interested in what the mums and dads of Australia have to say."

Senator Bernardi would not reveal how much his Australian Conservatives party paid for the robocalls, but said the campaign is "cost-effective".

"Well it's like any commercial research operation, it would be commercial in confidence firstly [to disclose its cost]."

"This is no different to what the unions have done, to what political parties have done and what all the research houses do to generate the political poll people find so interesting."

The senator, who has been a prominent figure on the No campaign, said same-sex couples who receive the robocalls can simply hang up if they are upset.

"They don't have to listen to it. My business is to contact as many people and ask their views. If they choose to stay on the line they can let me know how they intend to vote or not."

Robocalls 'not invasive', Bernardi claims

There was outrage this week from the No campaign when the Yes camp sent unsolicited text messages to hundreds of thousands of Australians urging them to back the change.

But Senator Bernardi insists his tactic is different and amounts to nothing new in the political realm.

"It's not invasive, like sending text messages to unlisted numbers or to 12-year-olds telling them how to vote. I'm asking them for their opinion," he said.

"Taking the poll of an electorate or doing some market research is a time-honoured political technique and that's exactly what we're doing.

"I really do want to reach out to as many people as I possibly can, I don't want to just get into the echo chamber of people who agree with me."

The survey system will allow people to press a number to identify how they intend to vote.

But Senator Bernardi avoided questions of whether the data could lead to the identification of households who indicate they will vote no.

"I'm really not qualified to answer those questions. We've retained a professional outfit that does these sorts of surveys as part of their business."