The U.S. Department of Transportation, at the request of a House committee, will invest igate two -year- old claims that regulators rushed certification of the Eclipse 500 jet aircraft.

But Eclipse Aviation's founder and CEO says the claims were labor disputes, attributed the probe to the "silly season of politics" and maintains that the jet - more than 225 of which have now been delivered to customers - is safe.

A group of Federal Aviation Administration test pilots and inspectors, through their union, filed a grievance in October 2006, claiming FAA managers did not allow them to complete their work, even though they had identified several outstanding safety and regulatory issues with the twin-engine, 6-passenger jet.

The aircraft had received its type certification the previous month.

Jim Berard, a spokesman for the House Committee on Transportation and Infrastructure, said committee chairman Minnesota Democrat James Oberstar asked the department's inspector general to look into the claims. Oberstar wanted to make a priority of overseeing agencies like the FAA, he said.

E c l ip s e C E O Ve r n Raburn called it political grandstanding.

"All I can attribute this to is the silly season of politics, when everyone is running around, particularly people like Oberstar, trying to make themselves look good," he said.

He said much the same last month when the National Transportation Safety Board urged immediate inspections of Eclipse 500 throttles after an incident in Chicago in which a pilot was briefly unable to decelerate the engines.