For the first time in 15 years, NFL Players Association officials have uttered the “C” word —collusion. It asserts league owners are trying to frustrate free-agency rights granted by the landmark collective bargaining agreement of 1993 and threatens to disrupt a decade and a half of labor peace in the NFL.

Here’s the broader question: Is this a fundamental change in the league’s labor-management relationship?

For years, media members and fans suspected things were a bit too cozy between the NFL’s top officials and leaders of the players’ union. In 2006, broadcaster Bryant Gumbel gave the following advice to Roger Goodell, who was about to become commissioner:

”By making the docile head of the players’ union his personal pet, (former commissioner Paul Tagliabue) has kept the peace without giving players the kind of guarantees other pros take for granted. Try to make sure no one competent ever replaces Upshaw on your watch.”

The comment, made during HBO’s “Real Sports with Bryant Gumbel,” spelled trouble for Gumbel, who was about to become lead announcer on NFL Network games.

In hindsight, it can be concluded that union president Gene Upshaw fleeced Tagliabue during the 2006 negotiations on the collective bargaining agreement. Upshaw secured for the players nearly 60 percent of the league’s “total football revenue.” He also won a long list of player-friendly changes to the non-economic portion of the rules as part of a take-it-or-leave-it proposal.

”Total football revenue” includes the NFL’s primary cash sources — television money and ticket sales, plus local radio and television income, stadium revenue and lesser revenue streams. The union got that cash pool in place of one called designated gross revenue, which was based on TV and ticket money.

The accord won big; owners ratified the CBA 30-2.

Now, more than a few of the owners have remorse about the deal’s terms. And with nine votes necessary to terminate the agreement two years early, the aggression the sides have demonstrated of late could be evidence that the league and union are headed for a work stoppage.

A week ago, the league lobbed the first grenade, filing formal paperwork to remove Judge David S. Doty from his job as ultimate interpreter of the collective bargaining agreement. That decision could be viewed as a high-stakes attempt by the NFL to ensure that Doty would have no jurisdiction over the morass that might unfold when the agreement ends after the 2010 season.

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The union raised the stakes with its claim that the owners dropped the per-team debt ceiling to get back at the players.

Would the union have made this claim if there weren’t a feeling of looming labor unrest?

Absolutely, NFLPA general counsel Richard Berthelsen told Sporting News on Thursday.

”It’s not something we’re filing because we’re getting near the end of the CBA,” Berthelsen said. “We’re responding to something (the league) did openly and publicly, which we believe has a deterrent effect on player spending.”

NFL spokesman Greg Aiello declined to speculate on whether the current climate drove the charges. “The (NFLPA) can speak to what is driving the claim,” Aiello wrote in an e-mail to Sporting News on Thursday night.

Even if there’s no connection between the looming CBA crisis and the sudden belligerence, the increased tension and rhetoric doesn’t bode well for efforts toward an extension. The owners want to roll back rights, and the union sees no need to sacrifice gains.

Those basic positions make an eventual impasse seem inevitable.

Time is of the essence. Though the threat of an uncapped year doesn’t arrive until 2010, CBA rules will create problems in 2009, the last with a salary cap. Indeed, it was a similar situation under the old CBA, which was regarded as the point of no return, that paved the way for the deal’s extension two years ago.

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This time, it will be difficult to get these sides aligned in 12 months or fewer, especially against a background of inflammatory accusations and sharp disagreements.

Unless league and union leaders begin serious negotiations soon, a chain of events culminating in a work stoppage could soon be set in motion. Even if Goodell and Upshaw have their first meeting today, this rift can’t quickly be cured.

If this bad situation gets worse, everyone loses. Owners with heavy debt loads will lose their primary means of paying it down. High-priced all-for-me players will have to pay the mortgages on their mansions with a one-for-all piece of the strike fund pie. And both sides will risk alienating a public that seems to be edging toward knocking the NFL off its perch as America’s dominant pro sport.