Refugee groups said more than 40 Iraqis have already been picked up and sent to detention centres to await their repatriation to the Kurdish-run north of Iraq.
The Home Office said last night that no one would be returned to areas which are considered to be dangerous, but the planned removals fly in the face of United Nations advice.
For several years Iraqi Kurds have been among the largest ethnic groups claiming refuge in Britain and a handful have voluntarily returned home since Saddam Hussein was removed after the US-lead invasion.
Although David Blunkett, the former home secretary, said nearly two years ago that he wanted to start enforced returns shortly, no one has so far been sent back against their will.
Over the past week, however, Iraqi Kurds have been rounded up in several raids around the country, including operations in London, Birmingham, Plymouth and Cardiff.
A Home Office spokes-woman declined to say how many were being held but confirmed that deportations were planned to begin within weeks.
She said: "We will implement enforced returns to areas assessed as suitable and where individuals are assessed as not being at risk."
The spokeswoman added: "We believe that enforced returns are necessary to maintain the integrity of the asylum system."
Margaret Lally, deputy chief executive of the Refugee Council, said it was appalled at the prospect of people being sent back to a country "torn apart by war and insurgency".
She said: "All anyone needs to do is watch the news to see just how dangerous Iraq is at the moment. There is no evidence that the situation in Iraq is improving at all."
Julian Walker, policy officer at the Kurdish Cultural Centre, said: "If they are sent back to unsafe areas, they may well be killed. They won't be given any help or training so they can't really help with reconstruction work even if there are any jobs for them."
He said the centre had received reports of ethnic Kurds from non-Kurdish parts of the country, as well as non-Kurds, being picked up during the Home Office operation.
The recent surge of violence across much of Iraq has claimed about 30 lives a day, but the Government insists that the security situation in the semi-autonmous Kurdish area is much more stable.
Ministers argue that Kurdish asylum-seekers claimed refuge in Britain on the grounds that they faced death or torture from Saddam Hussein's regime. Now that he has been ousted, it has become safe for them to return, the Government maintains.Reuse content