Israel is telling African refugees to accept a £2,000 cash offer and a one-way ticket out of the country or face an indefinite stay in a desert prison.

The Eritrean and Sudanese migrants have been sent letters giving them 30 days to accept the offer of the cash and a ticket home or to another African country.

Last month, a statement from the interior ministry's population and immigration authority said Israel would identify qualifying migrants who cannot return home, inform them of their proposed 'safe third-party' destination and pay for their plane ticket and hotel there.

Detention centre: The offer will apply to migrants currently at the southern Holot detention centre in Israel

It said the measure would apply to migrants currently at the southern Holot detention centre 'who infiltrated Israel and cannot be expelled to their country of origin'.

Although the third-party countries were not named, media and some charities said they are Rwanda and Uganda.

The Washington Post has reported that the first of 45,000 refugees have received an offer of the cash as well as the one-way ticket. The location of the alternative - a stay in prison - has been revealed as Saharonim prison.

The letter reads: 'Money will be given to you at the airport in a secure manner. When you arrive at the third country, people will receive you at the airport and give you information about life in the country and other important information.'

The Washington Post said Israeli officials do not tell the refugees where they will be going until they are given their plane ticket on the day.

Last month's statement from interior ministry read: 'An infiltrator who agrees to this procedure will begin the preparations for leaving, an infiltrator who refuses will face a hearing following which it will be decided whether they will be imprisoned.'

The Eritrean and Sudanese migrants have been sent letters giving them 30 days to accept the offer of the cash and a ticket

Interior Minister Gilad Erdan said the measure would 'encourage infiltrators to leave Israel in a safe and dignified way, and will be an effective tool to upholding our commitment to return life to normal in Israel'.

However, international rights groups protested against the plans, claiming Rwanda and Uganda are not safe and that migrants who arrive there are stripped of their cash and documents.

Israel - a state built by refugees - has previously offered cash stipends to African migrants in return for them leaving the Jewish state.

Last year, Israel began sending of African migrants to Uganda - giving them a one-way ticket and a stipend.

The interior ministry said that since last year, 1,500 migrants 'wilfully left to a third country, in addition to 7,000 who left for their country of origin'.

While Israel is trying to rid itself of African refugees, Jewish emigration is still being encouraged.