Tony Abbott has described a demand that he register as a “foreign influencer” before he attended an international conference in Australia earlier this year as “absurd”.

News Corp reports the former prime minister refused the order to register as an agent of foreign influence under controversial security laws, saying: “Surely senior officials of the commonwealth have better things to do with their time.”

The request came the day before Abbott addressed the Conservative Political Action Conference in August, an event that also included Brexit party leader Nigel Farage and British political activist Raheem Kassam.

Abbott was informed by the attorney general’s department that as a former cabinet minister, he had a lifetime obligation to register any activity undertaken on behalf of a foreign principal.

In correspondence obtained News Corp, Abbott replied: “Any suggestion that I was a foreign influencer is absurd ... I decline to register and suggest that you rethink the making of such misplaced and impertinent requests in the future.”

The attorney general, Christian Porter, conceded the actions taken by his department did not represent as effective enforcement of the Foreign Influence Transparency Scheme.

“I have made it clear to my department that I expect it to demonstrate a focus on the most serious instances of non-compliance,” Porter said. “I’m not persuaded this focus has been perfectly demonstrated to date.”