HOW OTHER COUNTRIES CONTROL THEIR BORDERS

IN the United States immigration law provides for an annual worldwide limit of 675,000 newcomers, with certain exceptions for close family members.

The Immigration and Naturalisation Act allows a foreign national to work and live lawfully and permanently in the States.

Each year it admits foreign citizens on a temporary basis. Annually, Congress and the president also determine a separate number for admitting refugees.

Immigration to the States is based upon the following principles: the reunification of families, admitting immigrants with skills that are valuable to the US economy, protecting refugees and promoting diversity. In Australia, a tough immigration points system is credited with keeping numbers under control while ensuring the economy has the skills it needs.

Extra points are given for factors such as experience, qualifications and age. But critics argue there is no guarantee it would bring numbers down, pointing out that Australia has proportionately higher immigration than the UK.

Since 1967, most immigrants to Canada have been admitted on purely economic grounds. Each applicant is evaluated on a nine-point system that ignores their race, religion and ethnicity and instead looks at age, education, skills, language ability and other attributes.