A plan to remove more than 117,000 Denver voters from active voter files because they didn't cast ballots in November or January is coming under fire.

Four nonprofits are urging the Denver Election Commission not to "scrub" voter files because voters listed as "inactive" won't receive a ballot in the mail for the May 1 municipal election.

The groups are calling on the City Council to pass an ordinance allowing the commission to use voter files that predate the troubled November election.

"Scrubbing the voter list based on a faulty election has the potential of disenfranchising thousands of voters who may wish to participate in upcoming elections, including the presidential election in 2008," the groups said Thursday.

At a minimum, the groups said, the commission should mail an additional notice to voters who are in "inactive" status.

"We are following the law," said Alton Dillard, spokesman for the commission.

He said the commission did not remove any voters from the active list after the November election because of the Election Day problems.

He said voters can contact the commission to restore their active status up until 7 p.m. May 1.

The last day to register to vote in the May election is Monday.