The President says the Post Office is Amazon’s ‘delivery boy’

President Donald Trump lashed out against Amazon on July 23, 2018, saying the US Postal Service is its "delivery boy."

"The Amazon Washington Post has gone crazy against me ever since they lost the Internet Tax Case in the U.S. Supreme Court two months ago," Trump tweeted, seemingly referring to a high court ruling in June 2018 that freed states to collect sales tax on online purchases. "Next up is the Post Office which they use, at a fraction of real cost, as their "delivery boy" for a BIG percentage of their packages."

Trump has argued that Amazon takes advantage of the postal service, which he claims is losing money from the e-commerce giant. But the post office had been slipping into the red since before the rise of Amazon and is not funded directly by taxpayers.

July 23, 2018's tweets are just the latest in a string of attacks on Amazon that have carried on for months.

"I am right about Amazon costing the United States Post Office massive amounts of money for being their Delivery Boy," Trump tweeted in April 2018. "Amazon should pay these costs (plus) and not have them bourne by the American Taxpayer. Many billions of dollars. P.O. leaders don't have a clue (or do they?)!"

Amazon chief executive officer Jeff Bezos

(Flickr / Steve Jurvetson)

Part of Trump's frustrations toward Amazon seem to be associated with its chief executive officer Jeff Bezos owning the Washington Post. The tweets came after a weekend of critical news reports on the White House and the Trump campaign.

"In my opinion the Washington Post is nothing more than an expensive (the paper loses a fortune) lobbyist for Amazon," Trump tweeted. "Is it used as protection against the antitrust claims which many feel should be brought?"

Shares of Amazon fell as much as 2.4% following the tweets. They're up 54% this year.

This article originally appeared on Business Insider. Follow @BusinessInsider on Twitter.