Almost 9,000 Brazilian migrants have received golden goodbye payments of up to £3,000 to leave Britain - though most small-boat arrivals ignore the offer.
Taxpayers have footed the bill for 8,901 people from the South American country in the past two years who have gone through the assisted returns scheme.
Altogether, 20,365 migrants have accepted the incentive to go home, including 3,629 Indians, 746 Colombians and 468 Hondurans.
But the five biggest nations for small-boat migrants barely featured in the figures, with just seven Eritreans, 11 Sudanese, 14 Afghans, three Somalis and 77 Iranians taking up the offer.
The money - provided by the Voluntary Returns Service - is intended to cover travel and living expenses, and is available to failed asylum seekers, visa overstayers or anyone without the right to remain.
The official bill from July 2024 to this March was £35million, but sources told The Sun this figure now tops £40million.
It means the average payout is now £1,964, with the top £3,000 amount generally reserved for families and vulnerable people.
The ‘golden goodbyes’ have soared under Labour, and are now paid out at nearly four times the rate they were during the final two years of the last Conservative government.
Shadow Home Secretary Chris Philp said: ‘Labour are paying illegal immigrants to leave instead of stopping them arriving in the first place. They have found an expensive way to avoid the actual problem.
‘Paying off thousands of Brazilians does nothing about the boats crossing the Channel.
‘Meanwhile, people arriving in dinghies are being returned at a rate of just seven per cent. The Conservative Party would end this racket altogether.
’Our borders plan would ensure illegal immigrants could all be forcibly deported, meaning there would be no need to pay them off.’
The voluntary returns bill could soon rocket after Home Secretary Shabana Mahmood rolled out a pilot scheme offering failed asylum seekers and their families up to £40,000 to leave.
Those made an offer had seven days to accept, and the money is expected to be issued on pre-paid debit cards once they have left the country. They will also be given flights home.
Home Office sources have said assisted voluntary returns cost less than the £48,000 required for a forced removal, and do not require border agents to accompany a migrant all the way home.
A spokesman for the department said: ‘Encouraging voluntary returns is vastly better value than paying for hotels or forced returns, saving taxpayers millions. Under this government, returns of those with no right to be in the UK are up by more than 50 per cent, and close to 65 per cent for small boat arrivals.’

Deputy Editor