Labor MP delayed ending UK citizenship

A federal Labor MP has admitted she waited three months before following the advice of party officials and renouncing her British citizenship.

"I delayed it - it's one of those things with the citizenship I knew I could never get it back," Tasmanian backbencher Justine Keay told her local newspaper the Burnie Advocate on Friday.

Ms Keay, who was a British citizen at the time of the 2016 election, is one of four MPs the government may refer to the High Court if it can't reach bipartisan agreement with Labor on a new disclosure scheme for MPs.

The MP said renouncing her UK citizenship was the last tangible connection with her father.

"If I didn't get elected I can't get my citizenship back and for me, it was a very personal thing."

Ms Keay insisted she had done everything possible to abide by the constitution which prohibits a citizen of a foreign power taking a seat in parliament.

She acknowledged the only way to determine her eligibility was to have it tested in the High Court.

"Part of me sort of thinks - that probably is the only step to really put an end to all this and completely clarify it."