Des Browne, the Defence Secretary, is trying to prevent coroners from being highly criticical of the Ministry of Defence over the deaths of British troops killed in action.

In a highly unusual move, Mr Browne began legal moves yesterday to prevent coroners from using language prejudicial to the MoD when issuing verdicts on the deaths of troops who die on active service.

Lawyers for Mr Browne went to the High Court to challenge comments made by a coroner in Oxfordshire after an inquest of a Territorial Army soldier in Iraq. Private Jason Smith, 32, died of heatstroke in 2003.

Andrew Walker, the assistant deputy coroner of Oxfordshire, recorded at his inquest in November 2006 that Private Smith’s death was caused “by a serious failure to recognise and take appropriate steps to address the difficulty that he had in adjusting to the climate”.

Sarah Moore, appearing for the Defence Secretary, argued that the coroner should not have used the phrase “serious failure”. She told the High Court that the phrase could be seen as deciding civil liability for Private Smith’s death, which was not permitted under Rule 42 of the 1984 Coroners’ Rules.

The Government’s decision to go to the High Court is an attempt to stop the MoD from being exposed to civil actions on the back of – and using as evidence – the outspoken comments of coroners.

The hearing will act as a test case for how much freedom coroners have to make wideranging criticisms of the MoD after independent investigations into the deaths of troops serving in Iraq and elsewhere.

Private Smith fell ill in temperatures of up to 60C (140F) in August 2003 at the al-Amara stadium in southern Iraq. The inquest’s narrative verdict described how he was taken to a medical centre at Abu Naji camp, where he died. The coroner said that Private Smith’s difficulty in acclimatising should have been recognised.

Ms Moore told the High Court that the case raised “a matter of general importance” because the phrase “serious failing” was regularly being used in inquests of British Service personnel in Iraq.

Mr Justice Collins, the judge hearing the appeal, also emphasised the importance of the issue at stake as a new inquest has been ordered for Private Smith, because of alleged flaws in the original hearing.

Lawyers acting for the late soldier’s mother, Catherine Smith, from Roxburghshire, Scotland, argued that the Defence Secretary’s legal challenge was misconceived.

Private Smith’s family is also making submissions to the court over the scope of the new inquest and asking the judge to order full disclosure of MoD documents, other than those covered by public interest immunity.

Mr Walker has been critical of the MoD in his findings from several inquests. Last week, at the hearing into the death of Captain Daniel Wright, who fell 2,500ft (760m) at Weston-on-the-Green airfield while on parachute training near RAF Brize Norton in 2005, he concluded that he would not have died had he been equipped with a radio, enabling instructors to tell him how to open his reserve chute.

Last month, at the inquest of Captain James Philippson, Mr Walker accused the MoD of betraying British soldiers’ trust. Captain Philippson, 29, of 7 Parachute Regiment Royal Horse Artillery, died in a gunfight with Tale-ban troops in 2006 in which British forces were “totally out-gunned”, his inquest was told.

Mr Walker said: “To send soldiers into a combat zone without basic equipment is unforgivable, inexcusable and a breach of trust between the soldiers and those who govern them.” Geoff Webb, coroner’s officer for Oxfordshire, said Mr Walker felt that it would be inappropriate for him to comment on the High Court case.

David Masters, the Wiltshire coroner, who is conducting inquests of British servicemen, said: “I am unable to make any comment on this particular case.

“Having said that, I do not consider that this will deflect coroners from conducting full, frank and fearless inquiries into the deaths that they are entrusted to investigate – those of people serving their country when they are killed abroad. If something needs to be said, I’ll say it.”

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• All that glitters is not sold in Wright’s world
• Believe it or not, Big Brother is your friend