It is true that a portion of the workers overstay their visa period or enter the country with only a tourist visa. However, illegality, and therefore forfeiture of their right for residency, occurs primarily through migrants leaving their jobs due to prolonged illness, outstanding remuneration, illegal underpayment, overlong working hours or exploitative employment conditions.
Although never official policy, until the beginning of the new millennium most migrants without a residence permit were de facto tolerated because, among other reasons, no system existed to expel or deport them and they had a supporting function for some of the areas of the Israeli labour market listed above. In 2002, however, the government of Ariel Sharon justified a radical about-face with the symptoms of an economic crisis during the second Intifada as well as rising unemployment figures among Israelis. Notice was given of the expulsion of all "illegals", which was, in particular, associated with the creation of an immigration office with police powers (immigration police). The real reasons for the change probably lay, however, in the realisation that, contrary to antipation, guest worker migration was not a temporary phenomenon. The knowledge of being reliant for the long term on labour migration runs contrary to the aim of avoiding the establishment of non-Jewish population groups in the country wherever possible.
The central precept of migration control is, therefore, to expel as many "illegals" as possible from the country. On their Internet site the immigration office also addresses migrants directly in this respect. Here, foreign workers who are not authorised to stay in Israel are promised, on the one hand a form of "safe conduct" if they leave the country voluntarily. At the same time, hints are made as to the possible consequences of a continued stay.