The London-based blog about the tech startup scene, the Kernel, is being sued through an employment tribunal for non-payment of thousands of pounds by two of its former contributors, and is said to owe thousands more to other former staff.

When launched nine months ago by Milo Yiannopoulos, the founder and sole remaining director of the Kernel's publisher, Sentinel Media, the magazine-style blog claimed that it would "fix European technology journalism" and write about the burgeoning tech startup scene with a fresh eye. But its apparently impressive roster of staff has dwindled in the past weeks as internal arguments, particularly about payment, have grown.

MediaGuardian understands that Margot Huysman, 20, who joined as an intern in June, was offered a job in July and left in September having been promoted to associate editor, is suing after claiming she has not been paid for work she had done there. Jason Hesse, a former writer between March and May who wrote a total of 43 articles, also claims he is owed thousands of pounds. Mic Wright, who is still listed as "contributing editor" on the editorial staff page, and Ezra Butler, the "editor, United States", are also understood to have left.

In all, the debts are reckoned to total more than £10,000.

After a series of deadlines for payment to the contributors had elapsed, Yiannopoulos, 27, promised on Monday those owed money that they would be paid by Wednesday.

However, at the time of publication of this article on Wednesday those owed money had not been paid. "I have checked with my bank and there has been no payment," Hesse told MediaGuardian on Wednesday. Others confirmed that they had not been paid.

Hesse said that when he first sought payment, Yiannoupolos told him that he would instead dissolve Sentinel Media and transfer the assets elsewhere.

He and Huysman confirmed that their employment tribunal cases, filed at the London central court, are still in train. They argue that the letters of employment they received from Yiannopoulos constitute a legal contract of employment. When this was put to Yiannopoulos, a statement from Sentinel Media was sent in response, which said: "We are aware of one tribunal claim relating to a former employee who failed to meet the obligations of his contract. Negotiations are ongoing with that individual and we are confident the case is entirely without merit."

Sentinel Media also said that "any suggestion that the Kernel is about to be wound up is wholly and absurdly fictitious. The company continues to enjoy strong growth in revenues and readership."

The lack of payment has left some of the former writers furious at their treatment by Yiannopoulos. "He expected me to work seven days a week, around the clock," said one. "And when I declined, he got extremely agitated and started calling me names."

Another said that after repeatedly seeking payment, "I just realised there was always going to be another excuse".

Yiannopoulos's acidic approach to many of the companies featured in the Kernel has made a number of enemies in the London startup scene, some of whom have contacted the Guardian privately to complain about what they saw as negative coverage. "They're afraid to say so in public," Steve Karmeinsky of NetTek told the Guardian. "He's got a mouthpiece that he can't be fired from."

Karmeinsky is one of a number of London startup staff who have been riled by the Kernel's private mailout called the Nutshell, which Yiannopoulos said at the launch would contain "intel, rumours, tips, sightings and speculation, as well as a roundup of the best content on the web – both our own and from elsewhere".

David Rosenberg, a university friend of Yiannopoulos's – who co-founded the Kernel, but left day-to-day operations in January to work for location company FourSquare, remaining on the editorial board – told the Guardian: "I don't like the way [Yiannopoulos] picks [virtual] fights with people … I tried to extricate myself from his fight-picking."

He had not received a salary from the site, Rosenberg said.

Yiannopoulos is understood to have been seeking financing from a number of sources for some months. His tendency to pick virtual fights through media such as Twitter may have scuppered some of those attempts.

On 18 July he had a very public spat on Twitter with the blogger Zoe Margolis, author of The Girl With A One Track Mind books. That evening she complained on Twitter about a piece he had written for the Kernel about women in technology, tweeting that "someone needs to point out what a sexist, misogynistic prick [Yiannopoulos] is".

Minutes later he replied: "We write about how tech is changing the world around us. You write about how many cocks you've sucked this week. Back off." He later added: "Is there a difference between writing about sex for money and having sex for money? Not really. What a grubby, humiliating way to make rent."

The resulting row between the two, and supporters either side, is thought to have torpedoed a potential investment by Michael Acton Smith, the chief executive of Mind Candy, the London-based creator of successful franchises such as Moshi Monsters, who is worth millions – and follows both Margolis and Yiannopoulos on Twitter. Acton Smith did not respond to a request for comment.

Yiannopoulos – who used to go by the name of Milo Wagner – formerly blogged for the Daily Telegraph and TechCrunch.

From the end of 2010 he ran a project called the Startup 100 for the Daily Telegraph, but only three sponsors were secured to cover the costs of the awards ceremony in April 2011, and there was a row in May 2011 when Mike Butcher of TechCrunch said that he had given his casting vote for the winner to short-term loan company Wonga rather than the company that was awarded the prize, Spotify.

The fallout from the awards is understood to have left the Telegraph nursing a loss running into tens of thousands of pounds. Wrong Agency, Yiannopoulos's company which he used to run the event, was dissolved in May 2011.

It was next rumoured that he would start a venture capital company, Hipster Ventures, that would take European startups and launch them on the US west coast. But Hipster Ventures, formed with university friend David Rosenberg, filed for dissolution on 26 July 2012, the day after Rosenberg resigned from the company leaving Yiannopoulos as the sole director.

Rosenberg told the Guardian he had been annoyed to discover that Yiannopoulos had included him as a director of Hipster Ventures "without really discussing it" and resigned his position as soon as he discovered it. He said he had made it plain to Yiannopoulos that it "won't happen again".

The Kernel was founded in the autumn of 2011 by Yiannopoulos and Rosenberg. It launched in December 2011, stating that it would "experiment aggressively with ways to financially reward our writers".

• To contact the MediaGuardian news desk email editor@mediatheguardian.com or phone 020 3353 3857. For all other inquiries please call the main Guardian switchboard on 020 3353 2000. If you are writing a comment for publication, please mark clearly "for publication".

• To get the latest media news to your desktop or mobile, follow MediaGuardian on Twitter and Facebook

• This article was amended on 20 September 2012. The original said that Yiannopoulos was 29 and educated at Manchester. To clarify, his actual age is 27 and he did not graduate from Manchester. In addition, the original incorrectly stated that no sponsors were secured for the Startup 100 awards for the Daily Telegraph when in fact there were three.