A ninth Australian lawmaker resigned on Wednesday after confirming that she had a dual citizenship, The Australian reported. The crisis has already cost the Malcolm Turnbull government its majority in the Parliament.

Senator Skye Kakoschke-Moore, from Opposition party the Nick Xenophon Team, announced that she had British citizenship by descent because her mother was born in Singapore in 1957 when it was still a British colony.

Australia’s 116-year-old Constitution prohibits people with dual citizenship from being elected. The High Court of Australia ruled in October that five lawmakers were ineligible to rule as they held dual citizenships when they were elected in 2016.

The matter first came to light in July when a senator had stepped down after he discovered that he held dual citizenship. Following this, various senators put their citizenship proofs in public domain. After more reports of dual citizenship emerged, Prime Minister Turnbull ordered all lawmakers to prove that they comply with the laws by December 5.

Kakoschke-Moore said that she had asked the British Home Office to confirm her status only after Turnbull’s order, and was surprised. “At that time I had no knowledge that Singapore was a colony at the time my mother was born.”

She added that she was “heartbroken by this news,” according to local daily Belfast Telegraph. Kakoschke-Moore said that when she lived in Oman in the 1990s, the British Embassy there had told her father that she was not a British citizen through her mother.

Turnbull’s government lost its majority after the disqualification of Deputy Prime Minister Barnaby Joyce and resignation of MP John Alexander. The government now has 73 votes in Australia’s lower House. Of the 148 members in the House, 74 are from the government, including the speaker who can only vote during ties. The Opposition Labor party has 69 members and five are independents.