A troubled Denver charter school filed a 20-page legal brief this week with the Colorado Board of Education in the school's last-ditch attempt to stay open next fall.

The paperwork, filed on behalf of Life Skills Center of Denver, outlines reasons why it believes Denver Public Schools unfairly refused to renew its contract by using what it said was incorrect attendance data and low testing results.

But DPS officials have maintained that they used correct data when they presented it to the Denver Board of Education. In February, the board voted 6-1 against renewing the contract with Ohio-based White Hat Management, which operates the charter school.

Life Skills opened as a charter school at West 10th Avenue and Cherokee Street three years ago with the mission of helping drop-outs from DPS gain diplomas. It uses an approach where students have a flexible schedule because many are either single mothers or have jobs.

But the school encountered problems with the district with poor test scores and low attendance early in the contract and the school replaced much of its staff and hired a new principal to address the district's concerns.

The school said it showed improvement once the changes were made, but the district said it had three years to succeed and instead failed to meet the terms of its contract.

Once the Denver school board voted to not renew its contract with Life Skills, the school chose to appeal its decision to the state Board of Education.

The district has until April 16 to respond to the filing and then Life Skills can offer a rebuttal 10 days later. The hearing before the state Board of Education is scheduled for May 9.