Defence Secretary Des Browne has asked that strongly-worded criticisms of the Ministry of Defence be outlawed from inquests on soldiers.
A second inquest is to be held into Pte Smith's death
The plea came in a test case relating to Scottish soldier Pte Jason Smith, 32, who died of heatstroke in Iraq.
A first inquest said his death was due to a "serious failure" in not noting the difficulty he had with the climate.
Mr Browne's legal representative said the phrase "serious failure" could be seen as deciding civil liability.
Pte Smith, from Roxburghshire, fell ill in temperatures of 60C (140F) in August 2003 at the Al Amara stadium, southern Iraq.
The Territorial Army recruit, who was attached to the 1st Battalion the King's Own Scottish Borderers (KOSB), collapsed at an abandoned stadium, where his unit was stationed.
He had previously complained about feeling ill.
At an inquest in November 2006, Oxfordshire's assistant deputy coroner, Andrew Walker, concluded that the soldier'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".
The coroner said Pte Smith's difficulty in acclimatising to the heat should have been recognised.
Defence Secretary Des Browne made his plea at a test hearing
However, on Monday the wording of his verdict came under attack at the High Court in London before Mr Justice Collins.
Sarah Moore, appearing for the defence secretary, said the coroner should not have made reference to a "serious failure" to take appropriate steps.
She argued that the phrase could be seen as deciding civil liability and that could not be allowed under Rule 42 of the 1984 Coroners' Rules.
Lawyers acting for the late soldier's mother, Catherine Smith, argued that Mr Browne's legal challenge was "misconceived".
The judge was told the issue remained important as a new inquest was to be held into Pte Smith's death because of flaws in the original hearing.
Ms Moore said "a matter of general importance" had been raised because the phrase "serious failing" was cropping up on a regular basis in inquests into Iraqi military deaths.
Pte Smith's family are also making submissions to the court over the scope of the new inquest and asking the judge to order full disclosure of MoD documents, except those covered by public interest immunity.
The three-day judicial review will decide the remit of the new inquest.