Donald Trump continued his attack on Google on Wednesday, accusing the internet giant of political bias and – specifically – of promoting Barack Obama’s speeches while ignoring his.

Trump posted on his Twitter account a short video graphic criticizing Google alongside the hashtag #StopTheBias, which is being used on social media by other conservative figures

The latest tweet followed a rash of posts earlier in the week in which Trump complained that Google’s news service is “rigged” against him. Trump pledged to address this “very serious” situation.

On Wednesday afternoon, a tweet from the president’s @realDonaldTrump account declared: “For years, Google promoted President Obama’s State of the Union on its homepage. When President Trump took office, Google stopped.”

A short video then shows dates of Obama’s State of the Union addresses, with a circle drawn on what is presumed to be a screenshot of a Google homepage that has the words: “Live! Watch President Obama’s State of the Union address. Tonight on YouTube at 9pm ET” beneath the Google logo.

After cycling through several examples of the mention of Obama’s speech, the video shows the dates of Trump’s two addresses with a purported screen shot of a Google homepage with no mention of the event.

The US president has already said the way Google displays news stories is biased in favour of stories from leftwing news outlets and suggested tech companies were trying to hide positive stories about his administration – something Google strongly denied.

Google search results for “Trump News” shows only the viewing/reporting of Fake New Media. In other words, they have it RIGGED, for me & others, so that almost all stories & news is BAD. Fake CNN is prominent. Republican/Conservative & Fair Media is shut out. Illegal? 96% of... — Donald J. Trump (@realDonaldTrump) August 28, 2018

He went on:

....results on “Trump News” are from National Left-Wing Media, very dangerous. Google & others are suppressing voices of Conservatives and hiding information and news that is good. They are controlling what we can & cannot see. This is a very serious situation-will be addressed! — Donald J. Trump (@realDonaldTrump) August 28, 2018

Speaking to reporters at the White House on Tuesday, Trump said Google had “really taken a lot of advantage of a lot of people, it’s a very serious thing”.

Adding the names of Facebook and Twitter, he said: “They better be careful, because you can’t do that to people … we have literally thousands of complaints coming in.”

But asked whether Trump thinks Google should be subject to some regulation, Larry Kudlow, the president’s top economic adviser, told reporters outside the White House: “We’re taking a look.”

Trump also said 96% of Google News results for “Trump” were from leftwing outlets, which he described as “very dangerous”.

It is likely the US president was referring to a viral news story posted on Saturday by the website PJ Media, which concluded that the vast majority of Google News results for the president were from left-leaning outlets. The site used a classification that ranks almost every mainstream news outlet – other than Fox News, the Wall Street Journal, the Economist, and DailyMail.com – as leftwing.

PJ Media said its survey of the top 100 Google News results for the search term “Trump” was “not scientific” but suggested “a pattern of bias against right-leaning content”.

The US president possibly came across PJ Media’s 96% statistic after it was covered by the Fox News host Lou Dobbs on his Monday night broadcast.

Google never reveals how its algorithm works, partly to stop news organisations from gaming the system in order to boost their ranking. Google News results can be a substantial driver of traffic for websites, with the system relying on a vast number of signals when it comes to ranking news stories, potentially including a news site’s long-term reputation and popularity.

In a statement, Google insisted that it is not distorting results: “When users type queries into the Google search bar, our goal is to make sure they receive the most relevant answers in a matter of seconds. Search is not used to set a political agenda and we don’t bias our results toward any political ideology.

“Every year, we issue hundreds of improvements to our algorithms to ensure they surface high-quality content in response to users’ queries. We continually work to improve Google search and we never rank search results to manipulate political sentiment.”

The US president’s tweets – sent at 5.24am Washington DC time – are the latest in a string of attacks by Trump on major tech companies, as part of his ongoing criticism of the media.

Earlier this month, he said that “too many voices are being destroyed” by social networks, who have become increasingly willing to ban prominent individuals who have broken their rules, such as the conspiracy theorist Alex Jones.

Facebook, Twitter and Google chiefs are due to testify in Congress next week and can expect to come under attack from lawmakers, including with accusations of anti-conservtive bias.