A final meeting between Sun Country Airlines and its 250 pilots may be the only thing standing in the way of an all-out labor strike.

After more than five years negotiating for a raise – and a recent warning from the Minnesota company that it would shut down completely – Sun Country pilots have asked federal regulators to declare an "impasse" in the talks if one final round of mediation doesn't get anywhere, a Wednesday news release says.

What does this mean? If the National Mediation Board (a government agency that oversees labor disputes) does declare an impasse, the pilots will be officially released from the talks – the most important consequence of this is that it clears the way for them to strike.

According to the Air Line Pilots Association, an international labor union, Sun Country's Boeing 737 pilots are the lowest-paid airline aviators in the nation.

To put that in perspective, the Pioneer Press says the company's Boeing 737 pilots make $127 per hour flying the jetliners – might not sound like a bad way to make a living, but it's quite a steep drop from the industry average of $188 per hour.

If they don't get the raise they're asking for and they're released from the talks, a 30-day "cooling off period" would be the next step. That's union-talk for a period during which neither of the parties in the dispute can take "retaliatory action" against each other, according to the Free Legal Dictionary.

After that, a strike may be possible, and the situation could lead to the grounding of Sun Country's flights, as was seen recently in a similar situation in Europe, the Mail Online reported.

The Pioneer Press says the company has not commented yet.