THE ABC has taken the extraordinary step of warning its staff not to “censor” debate about same sex marriage, reminding them not to voice their own opinions in news coverage.

The email circulated to staff came just hours after Multicultural Affairs Minister Zed Seselja accused it of being unfair in its coverage and campaigning for gay marriage.

“Please remember that approximately 40 per cent of the population opposes the change and more importantly that the ABC does not have a position on the issue,” the email from the ABC’s news editorial policy manager told staff this morning.

Camera Icon Multicultural Affairs Minister Zed Seselja accused the ABC of biased coverage. Credit: News Corp Australia

“In this charged environment I would also urge everyone to be circumspect on social media -advocating for one side or the other will make it more difficult for the ABC to be seen as impartial.

“The more high-profile you are, the more important discretion is.”

But an ABC spokeswoman said those reminders were “regularly” sent to staff.

“The ABC will be covering the same sex marriage debate the same way we cover all stories: with accuracy, impartiality and a diversity of perspective,” she said.

“Personal social media posts by staff are not official ABC content, so they are not covered by the ABC’s editorial policies.”

Labor is this afternoon expected to formally throw its support behind the yes campaign, even with some debate among same sex marriage advocates about whether to boycott the postal ballot to begin next month and expected to cost up to $122 million.

“I think the less said about this irregular and unscientific polling the better. I’m not going to take any part in it whatsoever,” former High Court judge Michael Kirby said this morning.

Camera Icon Labor leader Bill Shorten email wording to MPs was parroted by several members of parliament. Credit: AAP

But The Daily Telegraph can also reveal several Labor MPs parroting talking points sent to them from Opposition Leader Bill Shorten’s office word for word.

Emails sent by Mr Shorten’s office told MPs to say: “A voluntary, non-binding, postal vote is a total cop-out. This is totally unnecessary and a total waste of time and money”.

“A voluntary, non-binding, postal vote is a total cop-out,” Tasmanian MP Justine Keay told her local paper.

“This is totally unnecessary and a total waste of time and money.”

“We’ll support marriage equality in every forum,” the talking points email reads.

“I will support marriage equality in every forum,” another Labor MP, Ross Hart, said.