Susan Lamb clear to contest by-election after renouncing UK citizenship

Labor's Susan Lamb has had her British citizenship renounced, clearing the way for her to nominated for the by-election for her Queensland seat.

Ms Lamb resigned last week for being a dual citizen and therefore unable to sit in Federal Parliament.

It came, along with the resignations of two other Labor MPs, almost immediately the High Court ruled colleague Katy Gallagher was ineligible to be in the Senate.

All three were under the same citizenship cloud but had refused to resign, arguing they'd taken all reasonable steps to sever their ties with the UK.

The Labor Party has produced a letter from the British Home Office, formally renouncing Ms Lamb's citizenship.

The Home Office request for her to produce her parents' marriage certificate, showing she'd acquired British citizenship by descent, prompted a tearful reply in parliament, with the former member for Longman explaining she couldn't locate the certificate because her father had died and she was estranged from her mother.

Her mother told The Australian newspaper her daughter hadn't sought help finding the document.

The party submitted a new application to renounce her citizenship hours after she resigned.

Ms Lamb has been endorsed to contest the marginal seat, north of Brisbane.