By Colin Packham
SYDNEY (Reuters) - Australia's third largest party the Australian Greens lost a second senator on Tuesday, forced to resign after realizing she had dual citizenship and was ineligible for office, only days after another Greens senator resigned for the same reason.
The Greens hold a key bloc of senate seats and have stymied legislation by Prime Minister Malcolm Turnbull's conservative government, which does not control the Senate.
The resignations provide some temporary relief to Turnbull, who could now seek to push key legislation, on health and media laws, through the Senate before replacements are appointed.
Australian politicians are not eligible to be elected to parliament if they are hold dual or plural citizenship.
Greens co-deputy leader Larissa Waters said she would resign from the Senate after realizing she had not renounced her Canadian citizenship prior to be elected in 2011.
"I left Canada as a baby and I've never been back. I had no idea that I was Canadian citizen," Walters told reporters.
Only days earlier, fellow Greens co-deputy leader Scott Ludlam resigned after realizing he held New Zealand citizenship, ruling him ineligible for the past nine years he had been in the Australian Senate.
The two resignations place the issue of political eligibility in the spotlight, with nearly a third of the Australian population born overseas, data from the Bureau of Statistics shows.
"There are many politicians in the Senate and Federal House of Representatives that were born overseas and it may be others will be forced into this embarrassing revelation," said Waters.
Former conservative prime minister Tony Abbott last week published proof he renounced his British citizenship in 1993, six months before he was first elected to parliament.
Several parliamentarians on Tuesday took to social media to address questions of their eligibility as the issue quickly emerged as the most popular subject on Twitter in Australia.
(Reporting by Colin Packham; Editing by Michael Perry)