Lawyers for the Victorian Liberals have admitted Chinese-language election signs used by the party in May's federal election could have been more clearly differentiated from official electoral commission material, but rejected claims Chinese-speaking voters were misled.

Key points: Lawyer Philip Solomon told the court the signs were not like AEC material except for the purple colour

Lawyer Philip Solomon told the court the signs were not like AEC material except for the purple colour He said there was no evidence to suggest the signs influenced final votes

He said there was no evidence to suggest the signs influenced final votes It comes after a senior Liberal figure told the court the signs were designed to look similar to AEC posters

The signs are at the centre of a court challenge that aims to void the election results in Kooyong, where Treasurer Josh Frydenberg was re-elected, and in Chisholm, where Gladys Liu became the first female Chinese-Australian federal MP.

The case has been brought to court by independent candidate for Kooyong Oliver Yates, and a voter in Chisholm, Vanessa Garbett, who say voters were deceived and misled.

The signs, known as corflutes, used the purple colour of the Australian Electoral Commission (AEC) and were deliberately placed next to official commission material at polling booths.

They did not include the Liberal Party logo.

They read: "Correct method of voting. On the Green Paper Ballot put a '1' next to the Liberal Party candidate."

Philip Solomon — the lawyer representing Mr Frydenberg and Ms Liu — cast doubt on the challengers' assertion that voters would see "this corflute amongst 30 to 50 others and conclude that it comprises a mandatory command" to vote Liberal.

Gladys Liu narrowly won the seat of Chisholm in May's election. ( ABC News: Marco Catalano )

He told the Court of Disputed Returns there was nothing to show it was obviously AEC material and therefore "wasn't likely to mislead in the casting of a vote".

"There are ways in which it could have been more obviously partisan to the Liberal party, of course," he said.

He addressed criticisms that the Liberal party corflutes were positioned alongside AEC material.

"But for the colour they are nothing like each other," he said.

On Wednesday, Mr Frydenberg's senior adviser, Simon Frost — who was the state director of the Liberal Party and approved campaign material during the election — admitted the corflutes were designed to mimic official AEC material.

"He [Frost] saw it as part of the rough and tumble of political messaging," Mr Solomon told the three justices presiding over this case.

He noted the Labor Party's use of similar signs in past elections "was the inspiration" for Mr Frost, and the idea was "his and his alone".

Mr Frydenberg and Ms Liu have both said they did not approve the signs.

The signs did not bear the Liberal Party logo. ( ABC News: Gemma Hall )

Mr Frost gave evidence that the signs that were printed were different to the ones he approved.

Mr Solomon said there was no evidence that the signs caused Chinese-speaking voters to change their vote.

Census figures show there were 33,000 Chinese speakers in Chisholm in 2016.

In May's poll, 20,255 people in the electorate cast a first preference for the Liberal Party.

Mr Solomon told the court there were only a "few hundred or few thousand" voters who were in the group said to be targeted by the signs and there was no evidence they affected the results.

Josh Frydenberg comfortably retained his seat of Kooyong, but not on first preferences. ( ABC News: Andrew O'Connor )

"Many of them had to be misled for the test to be satisfied," he said.

The AEC received complaints on polling day but did not act to remove the signs.

Its lawyers have told the court it is "implausible" that the corflutes affected the federal election result.

"It is hard to imagine any adult citizen being so naive and gullible to think Australia is a one-party state," AEC solicitor James Renwick said during Thursday's hearing.

The court has adjourned its decision.