Lawyers for former detainees of British military in Iraq say only an inquiry can prevent systemic abuse and brutality in the future

Allegations that British troops in Iraq were responsible for the widespread and systemic abuse of detainees through "terrifying acts of brutality, abuse and intimidation" were raised in the high court today as lawyers representing hundreds of former prisoners demanded a public inquiry.

More than a thousand former prisoners complain that they were severely mistreated after being detained by the British military during the five-year occupation of the south-east of the country, while others – including women and children – say they were abused when their male relatives were being detained.

"Enough is enough," said Michael Fordham QC, for the former prisoners. "There must be a public inquiry in relation to credible and prima-facie cases of human rights violations perpetrated by the British military in Iraq between 2003 and 2008."

The abuses were systemic, Fordham said, as they arose from the "systems, management culture and training" of the British military, and only an independent and public inquiry would not only establish who was responsible, but guarantee that the abuses are not repeated during future conflicts.

"The state can be in violation of its human rights obligations if it doesn't put in place systems ... that stop it happening again," he said.

The hearing is the latest skirmish in a three-year legal battle between lawyers for the former detainees and the Ministry of Defence (MoD), which is anxious to avoid a public inquiry.

The MoD is not denying that the evidence may support the claim that the abuse was "systemic", but says the inquiry panel that it has established, the Iraq Historic Allegations Team (IHAT), is capable of establishing the truth about what happened in its detention facilities.

Speaking outside the proceedings, a spokesperson said a public inquiry would be "premature and disproportionate" and take much longer than IHAT would.

"The MoD takes all allegations of abuse seriously, which is precisely why we set up IHAT to ensure that all allegations are, or have been, investigated appropriately."

Many of the individual claims investigated by IHAT have resulted in the payment of substantial sums in compensation. Last month the department announced that it had paid a total of £14m to 205 claimants. A further £1.1m was paid to 22 more people in recent weeks. Payments to about 180 more former prisoners are being negotiated, and further 700 cases are thought to be in the pipeline.

However, Fordham told the court that the work of IHAT was not resulting in the systemic nature of the abuse being properly "ventilated in public", in a manner that openly established the truth.

The former prisoners' lawyers have also objected to the involvement of military police officers in IHAT, which answers to a panel of senior MoD officials.

Many of the allegations focus upon the work of a shadowy interrogation facility known as the Joint Forces Interrogation Team, operated by all three branches of the services at a detention centre near Basra. During earlier proceedings, JFIT was condemned in court as "Britain's Abu Ghraib".

Videos made by the interrogators themselves show prisoners being threatened with death and subjected to sensory deprivation, while their complaints of sleep deprivation and starvation go ignored.

Former JFIT prisoners allege that in between the video-filmed interrogation sessions they would be blindfolded and dragged by their thumbs around an obstacle course while being kicked and struck with rifle butts. One former JFIT guard has confirmed to the Guardian that this was routine practice.

The court has heard that custody records show guards were ordered to wake prisoners every 15 minutes: a practice known as Operation Wide Awake.

There are also allegations that JFIT's prisoners were beaten and forced to kneel in stressful positions for up to 30 hours at a time; held for days in cells as small as one metre square; that some were subjected to electric shocks; and that others suffered sexual humiliation by female soldiers.

In 2010 the Guardian reported that the unit that supplied JFIT's interrogators was secretly training other members of the military in interrogation techniques that were designed to provoke humiliation, insecurity, disorientation, exhaustion, anxiety and fear.

A PowerPoint training aid created in 2005 and a manual dating from 2008 instructs trainees that they should use threats, sensory deprivation and enforced nakedness in an apparent breach of the Geneva conventions. "Get them naked," the PowerPoint aid says. "Keep them naked if they do not follow commands."