As allegations of his sexually improper behaviour pour forth, the NSW upper house has passed a motion condemning Donald Trump and endorsing a description of the Republican nominee as a "revolting slug".

Greens MLC Jeremy Buckingham's motion condemning Mr Trump was passed without objection or a formal vote on Thursday morning.

"[This house] agrees with those who have described Mr Trump as 'a revolting slug' unfit for public office," the motion read.

In a reference to Mr Trump's recently revealed remarks about grabbing women, Mr Buckingham said that all "reasonable and decent people find Donald Trump's behaviour obnoxious".