All bets off at Baldoyle track.
Fingal county councillors voted 18-4 in support of the controversial move, after defeating a motion by the Green Party's David Healy to retain the racecourse as a green belt.
Ellen Larkin, of Baldoyle Against Re-zoning, said she was "disgusted" that councillors would go against the wishes of local residents.
She added: "This is not the end of the matter. It's the beginning of a massive campaign."