It costs about £11,000 to remove someone from the UK
Illegal immigrants could be told to pay a "bail bond" rather than being sent to a detention centre, under new plans.
The Home Office says the "immigration bail" would allow foreigners to pay a large sum while awaiting deportation.
It says deportees will not be offered a choice between detention and a bond, but it could be imposed in addition to other measures like electronic tagging.
The cash would be held by the Home Office and forfeited if bail was breached.
Removing an immigrant from the country costs the taxpayer about £11,000.
Levy on fees
The exact sum deposited has not yet been worked out but would be "big enough to be effective," a Home Office spokeswoman said.
She said the type of situations where bail bonds could be used included when a court ordered the temporary release of someone awaiting a decision on deportation.
The draft Immigration and Citizenship Bill also suggests illegal immigrants could be tagged, rather than being sent to an immigration detention centre.
Those who have been deported could be allowed back into the UK, after a period of exclusion, if they agree to refund the cost of their original deportation.
The Home Office also unveiled details of a fund which will be raised from a levy on fees paid by foreigners who want to become British citizens.
The fund is expected to raise "tens of millions of pounds" and will be available to police forces, schools, councils and local health services which find they are hit with extra costs because of the short-term pressures of migration on their areas, a spokeswoman said.
The levy is expected to be paid gradually as immigrants progress through the citizenship procedure.
The fund, which is due to open next April, will be handed to regional government offices for distribution to areas which need it most, the spokeswoman said.
Immigration Minister Liam Byrne said: "Britain is not anti-foreigner, we're a welcoming, tolerant place, but we do expect newcomers to sign up to a deal if they want to stay and build a life in Britain."
Shadow immigration minister Damian Green said the bill was "largely a collection of old ideas" and what was needed was "a dedicated border police force" to crack down on illegal immigration, crime and human trafficking.
"Instead of trying to legislate away the ongoing chaos in our immigration system the government should focus on properly enforcing the laws we already have," he said.
Liberal Democrat home affairs spokesman Chris Huhne said the bill was an admission that "chronic mismanagement of immigration" had left many public services overstretched.
"Their solution appears to be to heap further charges on working migrants, who already fund public services like everyone else through the taxes they pay," he said.
Sir Andrew Green, chairman of Migrationwatch UK, criticised plans for a bail bond as an alternative to detention, adding: "At whatever level they set bail, it would be peanuts compared to the benefits of disappearing into the black economy."