Net immigration to the UK remains above 250,000 a year despite a small fall since the coalition government took over, according to the latest independent figures.
Prime Minister David Cameron and Home Secretary Theresa May want to reduce the number to under 100,000 by the end of the parliament in 2015.
But the Office for National Statistics said estimated net migration to Britain - the number of people arriving for more than 12 months minus those leaving - in the year to September 2011 was 252,000, down only 3,000 on the previous year.
Long-term immigration fell from from 600,000 to 589,000, similar to the level it has been at since 2004, while emigration also dropped slightly from 345,000 to 338,000.
Of those coming to Britain, 250,000 did so to study.
The left-of-centre thinktank the Institute for Public Policy Research (IPPR) said net migration was effectively unchanged.
Associate director Sarah Mulley said: "The government has so far made no progress towards meeting its target of reducing net migration to less than 100,000."
She added that changes to the student visa regime would "deprive the UK education sector and wider economy of much needed income" but not have a significant impact on long-term migration.
"The government should exclude students from migration figures and count them only if they stay in the UK for the long term."
The Home Office said new rules had resulted in a big fall in the number of student visas issued to non-Europeans.
Its own research, covering the period to March 2012, showed student visas were down 62% in the first three months of this year compared with the same period in 2011.
Work and family visas were also down, the Home Office said. Immigration Minister Damian Green said: "Our tough new rules are now making a real difference with a record 62% drop in student visas in the first quarter of 2012, and overall falls in work visas, family numbers and people settling.
"As these policies start to bite we are seeing an end to the years when net migration was consistently on the rise.
"But the hangover from the old system of weak controls means it is still too high and we will continue our programme of reforms to bring net migration down from the hundreds of thousands to the tens of thousands."
Migration Watch UK said the coalition needed to take "tough measures" to tackle the "unacceptable" figures.
Chairman Sir Andrew Green said: "You cannot expect to repair 15 years of mismanagement in 15 months, but it is worrying news that net migration is still running at a quarter of a million a year.
"There is no sign of any reduction from the huge numbers that developed under Labour."