Dual citizen Labor MP's mum speaks out

Queensland Labor MP Susan Lamb's estranged mother says her daughter did not seek her help to access information needed to renounce her British citizenship.

Labor MP Susan Lamb, with leader Bill Shorten, is still under a cloud over her citizenship. (AAP) Source: AAP

The estranged mother of Susan Lamb, the Labor MP the government is threatening to refer to the High Court, says her daughter did not contact her to help with renouncing her British citizenship.

The British Home Office did not accept Ms Lamb's application to renounce her citizenship after she failed to supply them with a copy of her parents' marriage certificate, The Australian reports.

"She didn't contact me but I would have definitely helped her,"' her mother Hazel told the Australian on Monday.

Ms Lamb needed the marriage certificate to prove she had British citizenship through her Scottish-born father before the Home Office could renounce it.

Her mother needed to give consent for her to access the certificate.

Ms Lamb stood by her disclosure statement provided to parliament on December 5 that "demonstrates the steps I took."

"The view I have taken reasonable steps is backed by constitutional legal experts in Australia and in Britain," she told the Australian.