The Home Office is seeking to double the rate at which it deports failed asylum seekers from Scotland - in a drive to clear a backlog of cases.

The immigration service is pursuing a target of removing 10 people every week after staffing problems led to it achieving only half that rate last year, it was disclosed yesterday.

The target was condemned as arbitrary and uncompassionate by refugee groups. However, in a parallel development, the head of the new Border and Immigration Agency (BIA) indicated its officers were willing to consider the length of time people stayed in Scotland as a factor in deciding whether they should be allowed to remain.

The move appeared to be a concession to Hugh Henry, the Scottish education minister, who last month said he would urge the Home Office to consider that many asylum seeker children are positively integrated into local schools and communities. He said he wanted this to be taken into account as part of a "sensible and pragmatic" approach to a review of some 1100 "legacy cases" in Scotland.

Lin Homer, BIA's chief executive, was speaking as she visited the Glasgow offices of the newly-devolved Home Office agency which officially took over from the old Immigration and Nationality Directorate yesterday. She said the review of legacy cases, those decided before the introduction of a new fast-track asylum system last month, would consider a range of factors in deciding whether people could remain in the country on a case-by-case basis.

This would include how long people had been in Scotland, whether they had obeyed the law, whether they had been honest in their asylum applications and whether the merits of their original case had changed, she said.

The ultimate aim was to clear all legacy cases by 2011 and speed up the time to deal with new cases, ensuring a "fairer and firmer system".

She added: "It will cost less money if we are not supporting families for such a long period of time while they await a decision, but it will also have a better emotional impact on people going through the system."

The Home Office is seeking to increase the proportion of asylum seekers whose cases are completed within six months, from 35% currently to 90% by 2009. Phil Taylor, regional head of the BIA in Scotland and Northern Ireland, said the agency was expected to meet its target of removing around 500 people a year in Scotland, but this would not be enough to clear the estimated 4000 people living here, in some cases for more than five years, by 2011.

However, the move to increase removals was condemned by refugee groups. Sally Daghlian, chief executive of the Scottish Refugee Council, said: "The new Border and Immigration Agency is promising enforcement, service delivery and increased removals. Not once does it mention protection or offering refuge to some of the world's most vulnerable people."

Robina Qureshi, director of Positive Action in Housing, which campaigns for asylum seekers, added: "They have targets for removals, but not targets for people who should remain here."