Attempts to soften increased regulation of oil and gas drilling are falling short, as Democrats form a barrier around rules approved in December and guard them carefully.

The latest attempt to limit the new rules failed Tuesday when a state House committee rejected a proposal to block further restrictions related to wildlife breeding or migration.

That follows rejection last month of a proposed moratorium on the rules and comes before a hearing next week on a bill to take regulatory responsibility from the Division of Wildlife.

Following months of public hearings, the Colorado Oil and Gas Conservation Commission approved a sweeping set of regulatory changes last year that do more to protect wildlife and the environment. The restructuring of both the commission and its rules was one of Democratic Gov. Bill Ritter's major initiatives after taking office in 2007.

But industry leaders claimed that the new rules, dealing with everything from the number of rigs in one area to drilling during animal mating seasons, are too tough and expensive. And Republicans and a few rural Democrats, arguing that increased regulation will lead to job losses, vowed to block some before the rules go into effect April 1.

But Democrats have held fast to the commission vote, noting repeatedly, as Rep. Judy Solano of Brighton did Tuesday, that the final rules were passed unanimously.

And activists, who show up in greater numbers to protest rollbacks to the rules than they do to support them, say the issue continues to be one of protecting property and nature above oil companies' interests.

"Their purpose is not to attack the industry or to hit oil and gas producers," said Grand Valley Citizens Alliance President Duke Cox, who spoke against the restriction-limiting bill. "Their purpose is to protect things that always have made Colorado what it is."

DRILLING THROUGH REGULATION CUTBACKS

Democrats have stopped two of three bills in committee that would roll back or limit regulations on oil and gas drilling. Here is a look at them:

* Senate Bill 4: Would have delayed implementation of proposed new Oil and Gas Conservation Commission regulations for one year, until July 2010.

Outcome: Killed by Senate Local Government and Energy Committee on Jan. 27.

* House Bill 1167: Would have banned further regulations concerning wildlife feeding, breeding, habitation or migration after initial rules take effect on April 1.

Outcome: Killed by House Agriculture, Livestock and Natural Resources Committee on Tuesday.

* House Bill 1255: Would specify that the Oil and Gas Conservation Commission, rather than the Division of Wildlife, would impose any drilling limitations in wildlife areas.

Outcome: Scheduled for hearing in the Agriculture, Livestock and Natural Resources Committee on Feb. 17.