SALT LAKE CITY (AP) — Environmental activist Tim DeChristopher is giving up appeals of his conviction for bidding on oil-and-gas parcels he couldn't pay for at a federal auction in Utah.

DeChristopher said Friday he was dropping appeals after being turned back earlier this month at the Denver-based 10th Circuit U.S. Court of Appeals.

"Throughout every stage of this legal process, it has been a predetermined conclusion that I should be punished for standing up to the collusion between government and corporations," DeChristopher said in a statement to The Association Press. "Any potential discussion of ethics, justice or the role of citizens has been banished from the court."

From the start, DeChristopher asserted the government auction in 2008 was illegal and that he was acting in civil disobedience to safeguard wild lands near Utah's national parks from drilling.

On Friday, DeChristopher said his fate was sealed by a trial judge who refused to let him testify about his environmental motives.

"As a result, our defense team has been restricted to debating a narrow range of technicalities rather than the critical issues of the case," said the University of Utah economics graduate.

DeChristopher has served 14 months of his two-year sentence at a federal prison in California and is due to be released in April.

His first appeal was rejected Sept. 14. A three-judge panel of appeals court judges ruled he knowingly broke the law when he jumped into the bidding to run up prices for oil-and-gas parcels. Other bidders complained DeChristopher cost them hundreds of thousands of dollars in higher prices. He ended up winning 14 drilling sites for nearly $1.8 million, but acknowledged he had no money.

The Obama administration later upended the auction that was held in the final months of President George W. Bush's administration, rescinding many of the parcels and denying them to winning bidders.

"Whether the BLM complied with all applicable environmental regulations in conducting the auction has nothing to do with whether defendant organized a scheme, arrangement or plan to circumvent or defeat" the law, the 10th Circuit U.S. Court of Appeals ruled.

The Bureau of Land Management runs auctions of federal drilling parcels.

DeChristopher, who turns 31 on Nov. 18, plans to continue a life of social activism after prison.