The Conservatives will fail to meet their pledge of dramatically reducing immigration in the next parliament, the government's own spending watchdog said today.
Immigration to the UK rose to almost 300,000 in the year to September 2014, higher than the level seen at the end of the last government.
However, the home secretary insisted earlier this month that the Tories would stick to their previous pledge of reducing migration to the "tens of thousands".
"I think we will keep the target, Theresa May told the Times.
“It is important because it is about not just dealing with those coming into the system but also about making sure that those people who shouldn't live here actually leave. You will have to wait for the manifesto to see the exact words."
However, the Office for Budget Responsibility today suggested the target was no longer realistic, given the steep increase in numbers over the past year.
"Our previous forecasts have been underpinned by the assumption in the ONS low migration population projections that net migration will move towards 105,000 a year by mid-2019," it found.
"A reduction over time seems consistent with the international environment and with the government's declared efforts to reduce it. But in light of recent evidence, it no longer seems central to assume it will decline so steeply"
The OBR believes that immigration will now "tend towards 165,000 [a year] in the long term."
A significant rise in immigration last year was one of the main factors behind better than expected growth figures. According to the OBR: "We have revised [growth] up slightly to reflect the stronger population and employment growth associated with higher rates of net inward migration."
The findings follow pressure from senior figures within the Conservative party to drop their commitment to dramatically reduce immigration. May is believed to have vetoed any attempts to drop the pledge in the upcoming manifesto.