The resumption of enforced returns to the country began at the weekend with the reported deportation of around 15 people to the Kurdish region of northern Iraq.
It followed new advice from the United Nations High Commissioner for Refugees that returns to the region were now feasible in the light of the improved security situation in that part of the country.
The move was condemned by the Refugee Council, which said the region was still too dangerous to send people back to against their will.
Liberal Democrat home affairs spokesman Mark Oaten called for an immediate moratorium on the deportations.
"Even in some of the northern areas where there has been some relative calm over the last few months, there is no long-term stability that can be planned for those areas," he told BBC Radio 4's Today programme.
"To send individuals back in a forced way, without any back-up, without any support, into that region, I think, is unacceptable at this stage.
"The Government should halt this programme and wait until we have much more long-term evidence that that northern region is stable. I don't think it is safe at this stage."
Immigration Minister Tony McNulty said there had now been a "sustained period of stability" in the northern region.
More than 1,000 former asylum seekers had returned there of their own accord, with a further 500 voluntary deportations in the pipeline, he said.
"We are not dropping anyone in a situation where they face death. We take very, very seriously the points about safety," he said.
"We are talking about people who have reached the absolute end of their asylum claim. They have no substantive claim at all, no legitimacy to be in the country. We must have the provision to return people in those circumstances."Reuse content