WASHINGTON (AP) — The Biden administration said Thursday it is launching a broad investigation into the state of competition in air travel, including the effect of airline mergers and joint ventures.

The investigation is being handled by the Justice Department’s antitrust division and the Department of Transportation.

The administration has successfully blocked three airline deals in the past four years, and President Joe Biden has blocked criticized the airlines for charging “unwanted fees”.

However, the timing of Thursday’s announcement — less than three months before Biden leaves office and with race to succeed him considered a toss up—throws uncertainty over the fate of the investigation.

“Unfortunately, the timing of this ‘broad investigation,’ which was announced 12 days before a national election, suggests political motivations,” the trade group Airlines for America said in a statement.

Four airlines dominate the US airline industry – United, Delta, American and Southwest. They are the product of mergers that eliminated several major airlines.

The airline industry says there is still plenty of competition. Industry indicates Transport department data which shows that average US airfares have generally declined for many years, although this has been partly offset by higher fees for baggage, premium seats and other items.

“Survey after survey shows that airline customer satisfaction is at an all-time low,” said Airlines for America. “Air travel is at an all time high.”

In the second quarter of this year, the average ticket was $382, according to government figures. This is down from $404 in the same quarter last year and $438 in the same period in 2019, before the coronavirus pandemic.

The departments said they would also look at how air travel is priced and sold, as well as airlines’ frequent flyer programs.

The agencies said they would accept public comments until Dec. 23.