The Labor MP Justine Keay has admitted her renunciation of British citizenship was not effective until after the 2016 election, but she and another ALP colleague are relying on “reasonable steps” taken to renounce foreign citizenship to stay in parliament.



The admission may leave Keay’s place in parliament vulnerable to challenge, as several constitutional law experts have warned it is arguable that reasonable steps are not enough to escape the constitutional disqualification on a strict reading of the high court’s decision in the citizenship seven case.

The citizenship fracas has blown up on multiple fronts this week, with the Liberal MP John Alexander digging in while attempting to clarify his citizenship status with UK authorities, and the prime minister attempting to create a circuit breaker by proposing a new disclosure regime for parliamentarians.

Malcolm Turnbull will meet the Labor leader, Bill Shorten, on Wednesday morning to see if bipartisan agreement can be reached on the proposal.

But the ALP has signalled it has significant problems with the regime. Labor has taken issue with the proposed 21-day disclosure timeframe, which, with only one sitting of parliament remaining this year, would kick the controversy into 2018.

Alexander told the Seven Network on Tuesday night that he intended to “comply with what the prime minister announced”, which suggests he may not move to clarify his citizenship status quickly.

The Liberal MP is currently seeking information from the British Home Office. Labor has demanded that Alexander be referred to the high court.

Turnbull travelled north on Tuesday to campaign with Barnaby Joyce, who is facing a byelection in New England because of his disqualification by the high court.

Joyce’s departure has already cost the government a working majority, and a byelection triggered by the departure of Alexander in the event he is found to be a dual citizen of the UK would compound the government’s problems.

While most of the spotlight has been trained on the government, Labor MPs are also facing questions. In August Keay posted a statement on Facebook saying she had applied to renounce British citizenship in May 2016 and had therefore “taken all reasonable steps” by the nomination date of 9 June 2016 for the election which was held on 2 July.

Keay told a Facebook user the “official date” on the declaration of renunciation notice from the UK government was 11 July.

Keay noted this was “prior to [the] declaration of poll and officially elected on [the] 19th [of July]”.

“Critical point in time is actions taken prior to nomination,” she said.

The post suggests Keay was a British citizen on 9 June 2016, the nomination date on which candidates must declare they are eligible and on which section 44 of the constitution requires they must not be foreign citizens to qualify.

Susan Lamb, left, with Bill and Chloe Shorten, in the days after last year’s election. She was eventually elected on a tiny margin in the Queensland seat of Longman. Photograph: Dan Peled/AAP

Labor MP Susan Lamb has said that she took all necessary steps to renounce British citizenship in May 2016, but has refused to say if her renunciation was processed and confirmed before the deadline. Keay holds the Tasmanian marginal seat of Braddon by 2.2% and Lamb holds the Queensland marginal of Longman by 0.79%.

The high court’s unanimous judgment explicitly warned that section 44 “does not disqualify only those who have not made reasonable efforts to conform to its requirements”.

The judgment states that a person who “retains the status of subject or citizen of a foreign power” at the time of nomination will be disqualified “except where the operation of the foreign law is contrary to the constitutional imperative that an Australian citizen not be irremediably prevented by foreign law” from participation in representative government.

University of Sydney constitutional expert Anne Twomey has said that the reasonable steps test is still unclear, and there may have to be another referral to determine when candidates are disqualified.

“It is possible to argue that a strict reading of the judgment is that a person is disqualified if he or she is a dual citizen at time of nomination regardless of what steps were taken beforehand,” she said.

“The other view is that a person is not disqualified if he or she has taken all the necessary steps to renounce citizenship under the requirements of the foreign country and that delay in processing the renunciation should not prevent a person from being elected.”

If the strict interpretation is correct, candidates will be required not just to take all reasonable steps but to actually complete the renunciation process, unless the foreign law is unreasonable in releasing them.

On Monday Turnbull said that given the “severity” and “very strict literal” interpretation taken by the high court, “foreign citizens ... should not be sitting in the parliament”.

Turnbull said that was subject to a “proviso” for cases such as Sam Dastyari, who had “done everything he can to renounce [Iranian] citizenship, but has been unable to do so”.

The justices gave one example of a foreign law that would impose an unreasonable hurdle: an Australian being required to be present in the foreign country to renounce their citizenship, at possible risk to their person or property.

But the justices said that none of the candidates referred – including Malcolm Roberts and Fiona Nash, whose cases both involved British citizenship – had faced “such obstacles to freeing themselves of their foreign ties”.

If Turnbull’s disclosure resolution is passed, the first question parliamentarians will be asked is whether – to the best of their knowledge – they were a citizen of a country other than Australia when they nominated for election.

Nationals MP Andrew Broad and Liberal senator Eric Abetz have suggested that if Keay and Lamb were British citizens at the time of nomination they should be referred to the high court.

Guardian Australia has contacted Keay and Lamb for comment.