Businesses and universities face new restrictions on recruiting overseas workers and students under a new drive to bring down immigration.
Home Secretary Amber Rudd revealed the shake-up as she reaffirmed the Government's controversial commitment to reducing net migration to the tens of thousands.
She said a "tick box" exercise has allowed some firms to get away with not training local people, revealing ministers will consider whether new tests should be imposed to ensure those coming to the UK are "filling gaps in the labour market, not taking jobs British people could do".
In her first major address since being appointed to the post, Ms Rudd also revealed proposals to overhaul the "one size fits all" regime for student immigration.
Ministers are considering whether the rules should be tailored to the quality of the course and educational institution.
Ms Rudd told the Conservative conference: "I'm passionately committed to making sure our world-leading institutions can attract the brightest and the best.
"But a student immigration system that treats every student and university as equal only punishes those we should want to help."
Under current rules for the main route for sponsoring skilled non-EU workers, businesses must satisfy a "resident labour market test", which involves placing two adverts to ensure there are no suitable workers already living permanently in the UK.
Students from outside the European Economic Area must apply for visas and obtain sponsorship from a university or college which has been granted a licence.
An estimated 111,000 non-EU citizens migrated to the UK to study in the year to March.
Ms Rudd's speech sparked warnings from business groups.
Josh Hardie, CBI deputy director-general, said it is "time to be clear about the value of migration to the UK, as well as its challenges", adding: "Businesses will not welcome further restrictions on high-skilled migration from key trading partners around the world."
Mr Hardie warned the government to "tread carefully" on any changes to student immigration "to make sure we don't undermine this critical sector for national prosperity".
Seamus Nevin, of the Institute of Directors, said the evidence is clear that migrants "are a benefit to the economy".
He said: "The Home Office also must not try to make employers do the work of government. Small companies do not have the expertise or know-how to vet immigration applications."
Dr Wendy Piatt, of the Russell Group, which represents 24 leading UK universities, said: " Our universities compete on the global stage so we welcome the Government's commitment to help us attract the brightest and the best from around the world.
"It is essential that our immigration system takes a risk-based approach to support legitimate students who want to study here."
Ms Rudd also set out a three-pronged crackdown on illegal immigration.
From December, landlords who knowingly rent out property to those with no right to be in Britain will be committing a criminal offence and could face prison, while immigration checks will be made mandatory for people wanting to get a licence to drive a taxi.
From next autumn, banks will have to carry out regular checks to ensure they are not providing essential banking services to illegal migrants.
Measures to make it easier for Britain to remove foreign criminals were also outlined, with EU nationals who repeatedly commit so-called minor offences facing deportation and a ban from returning to the UK for five to 10 years.
Ms Rudd announced a new £140 million Controlling Migration Fund designed to ease the pressures on public services in areas of high migration.
The Home Secretary told activists the vote to leave the EU was a "clear message" from the British people to tackle high immigration.
She stressed it remains the Government's commitment to reduce net migration - the difference between the numbers of people arriving and leaving - to five figures, but warned: "This will not happen overnight."
Official figures show the net migration is running at close to a third of a million.
Alp Mehmet, vice chairman of campaign group Migration Watch UK, said: "These are very welcome steps forward. The referendum underlined public concern about immigration so it is only right that the Government addresses all aspects of the problem."