A cap on non-EU immigration will be introduced from next month as the coalition seeks to avoid a last-ditch influx to Britain.
Just 24,100 workers from outside Europe will be allowed into the country before April, with highly-skilled migrants having to meet tighter conditions, it was revealed.
Home Secretary Theresa May will announce the move on Monday, as she launches the consultation process for deciding the level of the permanent cap.
Aides played down reports of concerns among senior Tories over the effect of restrictions on businesses, insisting the policy was not being watered down.
Education Secretary Michael Gove and Universities minister David Willetts were both said to have expressed doubts in Cabinet discussions this week.
The Liberal Democrats opposed a cap during the General Election campaign, but signed up to the Tory idea as part of the coalition deal.
Ms May is understood to have decided interim limits were necessary after studying how immigration numbers "spiked" when Labour gave advance warning about restrictions.