Senator Hinch will seek the advice from the Solicitor General on Friday after it was revealed he still holds a social security number that entitles him to a US pension.

“I’m writing to the solicitor general today, I was drafting it last night, and if he says ‘I think you’re a case for the High Court’, then I’ll refer it to the High Court,” he told 3AW.

“I think I’m in the clear…(but) I’ll face it if I have to.”

Under section 44 of the constitution people are ineligible to hold office if they are a “citizen or entitled to the rights or privileges of a subject or a citizen of a foreign power”.

Hinch got the social security number during his time working in the US for Fairfax in the 1960s and 1970s.

He said he was receiving the pension for about three years before instructing the US Social Security Department to stop paying it because he became a senator.

He also said he did not consider it a privilege because he paid American taxes while there, but he is not a US citizen and never was.

Hinch called for an audit of the eligibility of all MPs.

Five members of parliament, including Deputy Prime Minister Barnaby Joyce, face a High Court test of their eligibility to serve as MPs.

Another two MPs, including cabinet minister Fiona Nash, are set to be referred to the court by parliament next week.

The citizenship saga claimed its first scalp last month when then-Greens senator Scott Ludlam was alerted to the fact he held dual citizenship with New Zealand.

At the time, Hinch said the barrister who uncovered Ludlam’s citizenship bungle was actually after him.

LNP Senator Matt Canavan resigned from cabinet after discovering his mother had registered him as an Italian citizen without his consent.

– AAP