The eight lawyers last night issued an executive summary of an unofficial "war crimes inquiry" held late last year. They heard evidence from eyewitnesses, as well as weapons experts.
The panel is made up of law professors from the London School of Economics, Oxford University, and universities in Canada, France, and Ireland.
They are supported by Peacerights, a human rights group, whose spokesman is Phil Shiner.
"Their main concerns are the use of indiscriminate weapons systems, in particular cluster bombs in urban areas such as Basrah, for which the U.K. was responsible. Secondly, attacks on the media. And thirdly, the question of whether civilian locations or civilian means of transport were targeted as military objectives when they should not have been," Shiner said.
Cluster bombs are controversial because they scatter lots of smaller bombs over a wide area. Many fail to go off immediately, posing a danger to civilians. Last month, Human Rights Watch said cluster bombs had killed or injured more than 1,000 civilians in Iraq.
In response to the panel's call, Britain's Defense Ministry told local media it reserves the right to use cluster bombs, and that other weapons could have caused even higher civilian casualties.
Shiner says the ICC would likely have to wait until Britain's attorney-general decides whether to prosecute in the U.K.
It's not clear if the ICC's prosecutor will take up the case. But if the court does investigate, Shiner says those at the very top of the British government could be prosecuted:
"The exercise here is to make sure that those people who are leading a country into war are fully accountable for their actions. So we're not interested in prosecuting individual soldiers. We're interested in the U.K. government, any accountability that should be brought about for [Prime Minister] Tony Blair or the Defense Secretary Geoff Hoon or the Foreign Secretary Jack Straw," Shiner said.
The lawyers' recommendations do not apply to the U.S., which is not a signatory to the ICC, a permanent court set up two years ago to deal with war crimes and crimes against humanity. They also examined conduct during the war only and did not directly address the legal case for war.
But Shiner says the two are interconnected.
If the war had been waged on the basis of an explicit resolution from the United Nations Security Council, he says, its likely aim would have been to disarm Iraq of its alleged weapons of mass destruction -- and not regime change.
"Therefore, decisions about military objectives and military necessity and whether an attack was proportionate or not would have been in that context, and the U.K. wouldn't have been able to justify many of the attacks on urban areas or civilian locations, because that was about regime change. If they had gone in pursuant to a UN Security Council resolution, it wouldn't have been about regime change but about weapons of mass destruction, and that would have been a whole different context and different decisions would have had to have been made," Shiner said.
The lawyers' call comes amid renewed debate over Britain's involvement in the Iraq war, which was deeply unpopular at home.
Next week, senior judge Brian Hutton publishes his long-awaited enquiry into the apparent suicide of British government scientist David Kelly. Kelly was found dead last year after he was named as the source for a controversial BBC report claiming the government had exaggerated the Iraqi weapons threat to boost the case for war.