At least 15 Iraqi and Kurdish failed asylum seekers are to be forcibly returned to Baghdad, campaigners say.
The International Federation of Iraqi Refugees insisted the migrants' safety would be jeopardised in Iraq.
It said it was hypocritical of the UK government to allow the deportations while at the same time advising Britons not to go to many parts of Iraq.
The UK Border Agency said it only forcibly returned people who it was satisfied no longer needed protection.
The International Federation of Iraqi Refugees (IFIR) said a further flight was due to leave for the Iraqi capital on 6 September, carrying as many as 50 failed asylum seekers.
In protesting at what it sees as the unfair treatment of Iraqis and Kurds living in the UK, the pressure group referred to the case of Herman Osman who it said was being held at the Oakington detention centre in Cambridge.
He is quoted by the federation as saying: "I have lived for 10 years in this country. I have no criminal convictions. I have always lived right. I have built a new life here and now they are sending me back to the same situation I ran away from."
Mr Osman added: "I ran away from a militia group in Kurdistan and they are sending me back to Baghdad. I don't have any family there, I don't even speak Arabic. So what am I meant to do?"
Advice on the Foreign Office website, updated on 6 August, warns Britons not to travel to Baghdad and its surrounding areas, and against all but essential travel to several other provinces.
It says: "Although there has been a decrease in the level of violence throughout Iraq, the situation remains highly dangerous with a continuing high threat of terrorism throughout the country (except in the Kurdistan Region)."
The federation accused the UK government of double standards, on the one hand saying it is too dangerous for its own citizens to visit while on the other hand insisting it is safe enough for refugees to return.
An IFIR spokesman said: "Many of [the refugees] have specific threats and dangers they left behind, as well as the general violence."
A UK Border Agency spokesman said: "We only ever return those who both the agency and the courts are satisfied do not need our protection and refuse to leave voluntarily.
"Currently we have an agreement with the government of Iraq to return all Iraqi citizens to Baghdad.
"We make arrangements for those who require onward travel to their home towns, and this includes those travelling to the Kurdistan Region.
"These arrangements worked well on the recent charter flights to Baghdad and we are confident they will continue to do so."