Sue Smith, who had earlier delivered a private letter to 10 Downing Street, read out its emotional contents to an estimated crowd of 20,000 anti-war demonstrators in Hyde Park after a protest march through central London which began in Parliament square.
Smith, from Tamworth, said she last saw her son, Peter Hewett, in a coffin in a chapel.
She offered a stark message to the Prime Minister: "You can never know how that feels, but you have the power to stop it happening again. You made the decision to go to Iraq, and you can make the decision to get our sons and daughters out of there."
Despite the demonstration failing to meet its organisers' expectations of around 100,000, Smith's plea aimed to attract public attention in the same way that Cindy Sheehan's vigil at George Bush's ranch in Texas has sparked a US focus on the continuing coalition presence in Iraq.
The London demonstration went off peacefully, but the high level of policing, including surveillance helicopters hovering over the march route, indicated that even Scotland Yard had expected a far higher turnout. Police estimates put the march total at just 10,000.
In 2003, just before the start of the Iraq invasion, around one million people took part in an anti-war demonstration along the same route.
Andrew Murray, chairman of the Stop The War Coalition, who organised yesterday's march, said: "There are tens of thousands who have marched above all to bring the troops home and end this bloody, disastrous occupation." <SNIP>
-- Michael Pugliese