A human rights ministry report says 85,000 killed in violence between 2004 and 2008.
A spokesperson for the UK border agency, which is alleged to have issued letters to the refugees about deportation, said they could not comment on the “timing or detail of removal operations”.
But it added: “Anyone who is in the UK illegally is expected to leave and the UK Border Agency will not hesitate to enforce their removal where necessary.
Previously, Iraqi deportees from Britain have been flown into the Kurdish region of northern Iraq, which has not seen the level of violence experienced in other parts of the country.
According to Britain’s interior ministry, 632 people were deported to northern Iraq between 2005 and 2008.
But it is believed the group being sent back this week will be flown to central and southern Iraq, where the situation is more volatile.
Maurice Wren, director of the Asylum Aid charity, told Britain’s Independent newspaper the move was “inhumane”.
“Forcing Iraqi civilians on to a charter flight to Baghdad is inhumane. Many Iraqis have fled Saddam’s persecution or the risks of being killed in the insurgency and have lived with their families as refugees in the UK for years.”
Hussein, one of the Iraqis said to be facing deportation, told the IFIR he could be killed if he returned to his homeland.
“I’m from Baghdad. I’m a Sunni – I have a big problem with a Shia party. They’ve used their influence to imprison my brother and they’re looking for me.
“If I’m deported I know 100 per cent I’m going to be killed.”
The IFIR is planning a demonstration later on Wednesday to oppose the government’s alleged move.