WASHINGTON (Reuters) - Amazon, facing potential criticism of its plan to buy Whole Foods Markets, continued its multi-million lobbying effort - shelling out $3.2 million in the second quarter of this year - an increase from the $2.9 million spent in the first three months.

FILE PHOTO - Amazon boxes are seen stacked for delivery in the Manhattan borough of New York City, U.S. January 29, 2016. REUTERS/Mike Segar/File Photo

Amazon has long had a presence in Washington, lobbying on a broad range of topics ranging from taxes, immigration, trade and mobile payments.

But their decision, announced in June, to buy premium grocer Whole Foods for $13.7 billion roiled the grocery industry and has sparked some opposition on Capitol Hill and among unions and other Amazon critics.

That said, most antitrust experts expect the Federal Trade Commission to approve the planned merger.

Complicating the company’s status in the nation’s capital, Amazon founder Jeff Bezos bought The Washington Post - a newspaper that has drawn the public ire of Donald Trump.

Candidate Trump famously said in May 2016 that Amazon has “a huge antitrust problem.”

Amazon is on pace to spend more than $12 million this year, if they keep up their lobbying efforts at the same rate. In 2016, the online retailer spent $11 million on lobbying in Washington.

The company’s lobbying effort more than doubled in 2015 compared with prior years, spending $9 million that year compared with $4.7 million the year before.

Amazon added a new firm to the lobbying army in the second quarter of 2017, hiring McGuireWoods Consulting to handle work on drones, among other matters.

In addition to consultants, Amazon also employs in-house lobbyists. Their latest filing lists some 15 employees who lobby on behalf of the company on a long list of topics and issues ranging from drone policy to trade regulations and immigration to food stamp programs.

Amazon also employs firms to lobby on its behalf on a range of topics. In the second quarter of this year, Amazon paid lobbying megafirm Akin, Gump, Strauss, Hauer & Feld $80,000 to lobby, primarily focused on the Marketplace Fairness Act - a bill that would allow state government to collect sales tax from online retailers.

Amazon Prime Air, a subsidiary of the company, also paid Akin Gump to lobby on drone policy. They also filed a termination, indicating they won’t be doing work for the subsidiary in future.