Cowan MP Anne Aly's electorate office was targeted overnight with "It's okay to be white" posters, a slogan she described as a "white supremacist neo-Nazi mantra".

The phrase was at the centre of an embarrassing gaffe by government senators in October when they accidentally voted for a motion proposed by One Nation leader Pauline Hanson to acknowledge "the deplorable rise of anti-white racism and attacks on Western civilisation" and that "it is okay to be white".

Cowan MP Anne Aly's electorate office was targeted overnight with posters bearing the slogan "It's okay to be white".

Dr Aly told Fairfax Media staff found the crudely produced posters when arriving at work on Thursday morning.

She said there was a direct link between the posters and the One Nation Senate motion.