Labor has asked the auditor general to investigate how the Liberal candidate for the seat of Mayo, Georgina Downer, was allowed to present a taxpayer-funded grant to a bowling club.

Downer, who has been preselected to recontest the South Australian seat after losing a 2018 byelection, was photographed presenting a $127,373 novelty cheque – featuring her face and Liberal party logos – to the Yankalilla bowling club.

The funding was a grant to the club under the federal government’s community sport infrastructure program. Protocol usually dictates that such funding is announced by the local MP.

Rebekha Sharkie, the Centre Alliance MP who beat Downer at the byelection, said on Twitter she had been notified about the grant recipients on Tuesday and had sought to let them know. “However, one was aware and had already organised their Friday night cheque presentation event.

She added: “In more than a decade of politics I’ve never seen a taxpayer funded grant delivered by cheque with a candidate’s face and name on it.”

The protocol is that the local Federal MP is notified of a grant prior to the Minister advising the club. In more than a decade of politics I’ve never seen a TAX-PAYER funded grant delivered by cheque with a candidate’s face and name on it. Rather desperate and misleading. — Rebekha Sharkie MP (@MakeMayoMatter) February 23, 2019

The trade minister, Simon Birmingham, defended the cheque presentation on Sky News and said it was the “type of self-promotional act is what members and candidates do right across the country all the time to help raise the awareness of the fact that they’re working and fighting for their local community”.

But the shadow attorney general, Mark Dreyfus, has written to the auditor general asking for an investigation into the conduct of Downer, the Liberal party and relevant government ministers.

“I query how it is possible for Ms Downer, the unsuccessful candidate for the 2018 Mayo by-election and an unelected candidate for the upcoming federal election, to misuse a taxpayer-funded grant in this fashion,” Dreyfus wrote.

“It is completely inappropriate and unacceptable for Ms Downer and the Liberal Party to treat taxpayers’ money as if it were their own, and to deceive Australians about the true source of this taxpayer-funded grant.”

On Sunday Downer found herself at the centre of a second controversy, after it was discovered that a “retiree” in an online campaign video is a former Liberal staffer, and the party’s former South Australian director, Jim Bonner.

The video introduces Bonner as “Jim, 72 (a) South Coast retiree” who complains about Labor’s franking credit policy and says he’ll be “voting for the federal Liberal government”.

The advertisement doesn’t declare Bonner’s long history with the Liberal party, including a stint as a press secretary to the then prime minister Malcolm Fraser, and as the South Australia state director of the Liberal party from 1998 to 2001. He most recently worked for Birmingham.

The Sun-Herald and Sunday Age reported that Downer, the daughter of the former foreign affairs minister Alexander Downer, defended the advertisement, saying Bonner was both a retiree and a long-term resident on the SA south coast.

The video was posted to Downer’s Facebook page and was not widely shared until the Sunday newspaper report, which has had the dual effect of both increasing its reach but also provoking an online backlash.

Many political journalists recalled Bonner from his time working with ministers in Canberra.

I’ve known Jim Bonner for almost 40 yrs from when he worked for Malcolm Fraser next to top press sec David Barnett. Since then he’s worked for the Liberal Party & its Ministers. He’s a terrific bloke but he’s better than this subterfuge. Good grief! https://t.co/S5ZJuG8I5v — Dennis Atkins (@dwabriz) February 23, 2019

Twitter users were quick to recall the “fake tradie” furore that consumed part of the 2016 election campaign.

Last time, the Liberals gave us the #FakeTradie. This time, the Libs are pushing their #FakeRetiree



“Ex-Liberal spin doctor stars as 'Jim, 72, retiree' in anti-ALP campaign video” https://t.co/hiRWDTQsqn — Kristina Keneally (@KKeneally) February 23, 2019

Labor’s election policy, branded a “retirement tax” by the government, aims to stop tax refunds to self-funded retirees who pay no tax but who are entitled to claim a refund for franking credits on shares.

On Thursday the Speaker of the House of Representatives, Tony Smith, criticised the chair of a parliamentary franking credits inquiry, the Liberal MP Tim Wilson, by noting he had broken conventions by creating a private website to solicit submissions against Labor’s policy, and by the apparent coordination of meetings with one of its primary opponents.

Labor has pushed for Wilson to be referred to the parliamentary privileges committee over alleged politicisation of the inquiry.

Wilson authorised a partisan website stoptheretirementtax.com, part-funded by Geoff Wilson, his first-cousin once-removed, which garners submissions opposed to Labor’s policy and signs submitters up to a Wilson Asset Management petition, a company chaired by Geoff Wilson.

In September Geoff Wilson boasted to investors he had asked Tim Wilson to schedule inquiry hearings alongside Wilson Asset Management roadshow events to help investors protest against Labor’s policy.