It’s no secret that Donald Trump has become a bit of a problem for Amazon lately.

His gripe with the retail giant is, according to his Twitter account, due to the firm’s tax practices and failure to support the US postal service - he alleges that the company is costing the US Post Office billions of dollars each year.

However, commentators have long linked the US President’s anti-Amazon agenda with Jeff Bezos’ ownership of the Washington Post, not least because Mr Trump has made that link publicly several times.

He has previously accused the newspaper of being little more than a vehicle through which Mr Bezos can lobby on behalf of his business interests, using the hashtag #AmazonWashingtonPost on more than one occasion. On Thursday, in his fifth tweet targeting Amazon this week, Mr Trump called out the “Fake News Washington Post, Amazon’s ‘chief lobbyist’” over an article headlined “Trump Defiant As China Adds Trade Penalties”. He suggested the alternative: “Trump Defiant as U.S. Adds Trade Penalties, Will End Barriers And Massive I.P. Theft.”

(Neither Amazon nor its founder, who bought the Washington Post for $250m (£179m) in 2013, has responded to the President’s recent barrage of insults.)

Sources have sprung up to report Mr Trump’s “obsession” with Mr Bezos, and media commentators have pointed to the recent barrage of insults as the latest evidence of the President’s distrust of and distaste for the free press. The New York Times editorial board this week accused Mr Trump of “trying to undermine the credibility of The Post because it is holding his administration to account”.

Regardless of why he’s attacking the company, it’s having an impact. In an already shaky tech environment, reeling from the recent Facebook data scandal and facing a potential regulatory overhaul, Mr Trump’s sustained campaign against Amazon has hit the company where it hurts. Reports of his animosity towards the retailer sent shares tumbling recently, wiping more than $30bn (£21bn) off the value of the company in a single trading session last week. And Mr Trump’s attitude could have long term consequences for Amazon if it hurts the firm’s ability to win important, valuable government contracts when it’s bidding against competitors who have the President’s ear.