Iraq's interior minister has rejected any appeal on behalf of hundreds of US mercenaries told to pack their bags and leave within a week.
Jawad al-Bolani announced on Wednesday that about 250 private security guards linked to Blackwater Worldwide must leave the country or face possible arrest on visa violations.
Yesterday, Mr al-Bolani said that the decision had "nothing to do with the courts."
Blackwater, now called Xe Services, was hired to protect US State Department personnel in Iraq.
On September 16 2007, Blackwater employees opened fire with automatic weapons and grenade launchers on unarmed Iraqi civilians at the busy Nissor Square in Baghdad, slaughtering 17 people.
At that time, guards protecting US embassy personnel enjoyed immunity from prosecution in Iraqi courts.
The US government has accused five Blackwater guards of causing the deaths of unarmed civilians, but in December a US judge decided to drop criminal charges against them, ruling that the Justice Department had mishandled evidence.
Foreign Minister Alistair Burt's admission that the Cameron government has "supported" a survey of attitudes to US drone strikes in Pakistan's tribal areas amounts to a tacit admission of British involvement.