A group of Twitter users has sued Donald Trump for allegedly violating the First Amendment, claiming that the President blocked them after they posted statements criticising him on the social media platform.

The lawsuit follows several attacks by the President against media organisations that he views to have published unfavourable work about him or his administration.

While the Trump White House continues to hold fewer on-camera press briefings – which were traditionally held almost daily during previous administrations – the President’s voracious use of social media is unprecedented.

“President Trump’s Twitter account, @realDonaldTrump, has become an important source of news and information about the government, and an important public forum for speech by, to, and about the President,” the Knight First Amendment Institute at Columbia University wrote in its lawsuit on behalf of seven Twitter users.

“In an effort to suppress dissent in this forum, Defendants have excluded – 'blocked' – Twitter users who have criticised the President or his policies. This practice is unconstitutional, and this suit seeks to end it.”

The group has also sued Sean Spicer, the White House’s Press Secretary and Acting Communications Director, and Daniel Scavino, the White House’s Social Media Director, saying that “upon information and belief” they both have the ability to block and unblock individuals from the @realDonaldTrump account.

The Twitter users each allege similar accounts to that of plaintiff Rebecca Buckwalter, a writer and legal analyst.

Iran's 'Trumpism' contest Show all 10 1 /10 Iran's 'Trumpism' contest Iran's 'Trumpism' contest A picture taken on July 3, 2017 shows a cartoon of US President Donald J. Trump and First Lady Melania Trump on display at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian cartoonist Hadi Asadi poses for a picture with a trophy and an award next to cartoons of US President Donald J. Trump, at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranians look at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian reformist cleric Mahmoud Doaei looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian man looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest An Iranian woman looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images Iran's 'Trumpism' contest Iranian reformist cleric Mahmoud Doaei looks at cartoons of US President Donald J. Trump at an exhibition of the Islamic Republic's 2017 International Trumpism cartoon and caricature contest, in the capital Tehran on July 3, 2017. / AFP PHOTO / ATTA KENARE (Photo credit should read ATTA KENARE/AFP/Getty Images) AFP/Getty Images

Mr Trump tweeted on 6 June, “Sorry folks, but if I would have relied on the Fake News of CNN, NBC, ABC, CBS washpost or nytimes, I would have had ZERO chance winning WH”, to which Ms Buckwalter replied, “To be fair you didn’t win the WH: Russia won it for you.”

“Ms Buckwalter’s reply tweet received 9,033 likes and 3,371 retweets,” the lawsuit says. “Soon thereafter, Ms. Buckwalter discovered she had been blocked from the @realDonaldTrump account.”

The lawsuit follows the group’s call last month for Mr Trump to unblock them. In a 6 June letter to the President, the Knight Institute – on behalf of the same Twitter users – wrote that his “Twitter account operates as a ‘designated public forum’ for First Amendment purposes, and accordingly the viewpoint-based blocking of our clients is unconstitutional.

“We ask that you unblock them and any others who have been blocked for similar reasons.”

The lawsuit also argues that the same sort of protections that the Constitution gives to speech in designated public forums should extend to the virtual ones now being used by Mr Trump.

“Twitter enables ordinary citizens to speak directly to public officials and to listen to and debate others about public issues, in much the same way they could if they were gathered on a sidewalk or in a public park, or at a city council meeting or town hall,” the group wrote.