Federal Labor Member for Fenner, Andrew Leigh called on the ACT senator to tell Advance Australia, the right-wing lobbyist group behind the signs, to stand down regarding the smear campaign against the former Wallabies star.

Senator Seselja on Wednesday morning stopped just short of throwing his support behind the group's fear-mongering smear campaign, describing the sports star's policies as "very similar" to the Greens.

Dr Leigh, a shadow assistant minister, described the Pocock corflutes and truck currently driving around the capital showing the independent candidate as revealing a Greens shirt under his suit as "fake" and "lying signs".

He said the signs had "no place in a civilised democracy".

"My message to Zed Seselja is he should tell these lobbyists to take down their signs," he told reporters in Canberra.

"I think it's very clear that these people putting up those signs are backers of Zed Seselja.

"So it's up to Mr Seselja. Please stand up today. And will he tell the people who are putting lying signs along Canberra streets to take them down? If he won't, then effectively he is complicit."

Mr Pocock has denied any links to The Greens. His campaign team has complained to the Australian Electoral Commission about the imagery in the ads, but the preliminary view is that the ads are not misleading.

But the Coalition senator, who has previously described the former rugby union star as a Green "extremist", said on Wednesday morning he didn't believe the signs were advertising anything false.

Speaking to ABC Canberra radio, Senator Seselja said he looked a lot like "the Extinction Rebellion end of the Greens".

"I mean, the Greens and David Pocock look very similar in their policy outlook," he said.

"I'm not aware of, in this particular example, that there is any - in terms of the materials that have been put out that I've seen - but there's anything that's actually incorrect.

"It's up to David Pocock, I guess, to have that argument with that third party."

Pocock's camp on Tuesday afternoon released a statement calling the political advertising "an attack on our democracy".

The ACT Senate candidate said his office had been "flooded" with calls and emails about the signs from Canberrans, who expressed confusion and outrage.

"Advance Australia's actions that spread false and misleading information to voters underscores why it is so critical that we introduce federal truth in political advertising laws," Mr Pocock said.

"Canberrans want integrity in politics and if elected that is exactly what I will work for as a priority."

Mr Pocock also pointed to Senator Seselja's ties to a former colleague, long-serving Canberra MLA Vicki Dunne, who now serves as a director for the activist group.

The ACT Greens candidate for Canberra Tim Hollo said the saga was another reason to ditch political corflutes during election season.

"People wouldn't put these dishonest attack ads in their own front yards - it's only because they're anonymously put up on the streets that this type of misleading campaigning continues," Mr Hollo said.

Ms Dunne, once a member of the conservative right faction of the Canberra Liberals, had allegedly relinquished her party membership in early 2020 just nine days before officially joining the activist group's leadership team.

The Australian Electoral Commission has been alerted to the Advance Australia signs but have formed a preliminary view they are not in breach of the electoral laws.

"Our preliminary view is that the signage in question is suggesting the candidate has a link or similarities with the Greens rather than attempting to confuse people into believing they are actually endorsed by the Greens," an AEC spokesperson told The Canberra Times on Tuesday evening.

The Advance Australia group has emerged during the 2022 federal election period as a major spender on online political advertising.

It spent $25,000 on ads attacking Labor, independents and the Greens in the seven days to April 23.

Advance Australia's political messaging has centred around national security and China's rising power in the region.

It has also targeted a push from progressive parties to introduce drug harm minimisation strategies and show support for trans athletes.

The conservative group raised $2.7 million in donations in the 2020-21 financial year and had spent more than a million on campaigns.