Employers could face two years in jail for knowingly employing illegal migrant workers, under a crackdown launched by the government.
The Home Office proposed the tough sentence along with a raft of other measures in a document it has put out to consultation.
It would be the first time the law had made a distinction between those employers who deliberately hired illegal migrants and those who did so accidentally. The new offence would also carry an unlimited fine.
Penalties of up to £10,000 per worker would be levied on those employers who are “less than diligent” in carrying out visa checks on their staff.
Immigration minister Liam Byrne said: “To combat illegal immigration, we must close down the illegal jobs that tempt people to try their luck coming to Britain.”
Employers’ groups backed the measures but said these relied on the success of the proposed employee-checking system that will allow organisations to find out quickly whether staff had the right to work in the UK.
The seven key parts of the proposed action plan are:
Tougher checks abroad
Compulsory ID cards for foreign nationals
The launch of an employee-checking service
Employment sponsorship of migrant workers
Higher penalties for those hiring illegal workers
A tougher enforcement regime
Greater publicity for the rules