CANBERRA, Australia (AP) — Australia's highest court has upheld a government decision to fire a public servant who used a pseudonym to criticize government immigration policy on Twitter.

The High Court's seven judges on Wednesday unanimously overturned a lower court's decision that Michaela Banerji's dismissal was not reasonable and that public service rules around the use of social media and making public comments "unacceptably trespassed on the implied freedom of political communication."

The Community and Public Sector Union, which represents public servants, said the decision had serious implications for free speech and could potentially affect almost 2 million Australians who work for the federal, state and local governments.

Banerji used the Twitter handle "LaLegale" to send more than 9,000 tweets in six years while she was a public servant.