THE husband of NSW Education Minister Verity Firth has been arrested for allegedly buying an ecstasy tablet from an accused drug dealer in Sydney's inner west.

Matthew Chesher, 44, the chief of staff to Roads Minister David Borger, was picked up by police on a street in Glebe on Friday night - carrying a single tablet worth as little as $20.

Ms Firth said yesterday: ''I am angry, hurt and very disappointed. But most of all I love Matthew and want to make sure he is OK.''

Mr Chesher's arrest is yet another scandal to engulf the Keneally government, less than two months out from the state election.

Police from the Redfern drug squad had been following a 30-year-old accused drug dealer when, at 5.30pm, they observed him in a ''transaction'' - thought to be for a single pill - with Mr Chesher.

Mr Chesher, who has also worked for Health Minister Carmel Tebbutt, was taken to Newtown police station where he was questioned before being granted police bail to appear at the Downing Centre Local Court on April 1. He quit Mr Borger's office yesterday.

Ms Firth, whose seat of Balmain was already likely to fall to the Greens, issued a statement late yesterday. It said: ''Last night my husband, Matthew Chesher, was arrested by the Pyrmont police and charged with minor drug possession.

''My husband has admitted to making a very big mistake. He co-operated fully with the police; was charged and was released. This morning, he resigned his employment with immediate effect.''