Denver (AP) Makers of the electronic voting machines are scrambling to come up with solutions or decide whether to appeal Colorado's top election officials decertifying the devices for use in some of the state's largest counties.
All the manufacturers say the machines have already undergone rigorous testing and are used without any problems across the country.
Secretary of State Mike Coffman says electronic voting machines used in Denver, Arapahoe, Pueblo, Mesa and Elbert counties cannot be used in the next election because of problems with accuracy or security.
His decision affects six of Colorado's ten most populous counties and three of the four equipment manufacturers allowed in the state.
A number of electronic scanners used to count ballots were also decertified, including a type used by Boulder county and more than three dozen other small to mid-size counties.
Coffman says the move could have national implications.
The manufacturers have 30 days to appeal.