Victims of the Manchester Arena bombing will launch multi-million pound lawsuits against the venue’s owners and security company in the wake of a damning inquiry report published this week.

The chairman of the Manchester Arena Inquiry is expected to make a series of devastating criticisms of the police and security operation on the night of the attack. 

Well-placed sources said lawyers acting for victims will use its conclusions to mount legal claims against the arena’s owner and the private security firm that was contracted to protect concert goers.

Twenty-two people were murdered when Salman Abedi detonated a suicide bomb in the foyer at the end of an Ariana Grande pop concert on May 22 2017, with hundreds more injured.

The Telegraph has been told that British Transport Police, which had responsibility for policing, SMG Europe, which owns the arena, and Showsec, the security company hired by SMG Europe, have all received official, detailed letters from the inquiry’s chairman Sir John Saunders informing them of the devastating  criticism they face. It is understood Greater Manchester Police will also face criticism.

So-called ‘Maxwellisation’ letters, a legal practice that allows persons who are to be criticised in an official report to respond prior to publication, have also been sent out to two men working for Showsec on the night: Kyle Lawler, who was 18 at the time, and Mohammed Agha, who was 19, who were both alerted to Abedi’s suspicious presence about 15 minutes before he detonated his bomb.

The report published on Thursday will spark legal claims against SMG Europe and Showsec. The damages are likely to run into tens of millions with dozens of victims who survived the attack suffering long-term mental and physical health problems.

The Home Office is currently consulting on bringing in a new law – named Martyn’s Law after one of the victims – that will require large hospitality venues and public spaces to protect themselves against a terrorist attack. It follows a campaign by Figen Murray, the mother of Martyn Hett, who died in the attack.

This week’s report is the first of three produced by the Manchester Arena Inquiry and will examine security arrangements at the venue on the night.

Part two, which is still hearing evidence, will examine the response of the emergency services, while the third volume will decide whether the attack could have been prevented.

The inquiry heard that Showsec, which in turn is owned by Live Nation, the world’s biggest music promotion company, employed a large, casual workforce, who were paid the minimum wage and with training largely confined to unpaid, online learning. 

But Showsec has argued its stewarding was not to blame if opportunities were missed to stop Abedi and that "primacy" for safety lay with police and SMG Europe. Showsec has admitted there was a "breakdown in communication" with SMG over the checking of a mezzanine area where Abedi hid for almost an hour in a CCTV blindspot.

One source close to the inquiry told The Telegraph: "This report will criticise SMG, Showsec and the police. It will pave the way for multi-million pound legal actions. The actions will  be levelled against SMG primarily because ultimately they were the ones legally responsible for protecting the audience."

SMG Europe, which now operates as ASM Global, declined to comment ahead of the report, Showsec also declined to comment. Both companies have privately accepted they will face stinging criticism but will respond on Thursday when the report is published.