The post you are reporting:
I researched the topic on immigration to Britain, and here is an extract from the online article: Finding Jobs in the United Kingdom:
"According to the British Government's official statistics, published quarterly by the Office for National Statistics, between the beginning of 2004 and the end of 2009, well over 500,000 people migrated to Britain each year. The figures are based mainly on data received from International Passenger Survey (IPS). IPS receives its data on migration to the United Kingdom by counting the number of passengers arriving at UK seaports and airports and surveying passengers about their reasons for entering the UK. It measures only the passengers coming to Britain for at least 12 months." (author D. Alexander)
So this means that the number of people who declare that they are staying for less than 12 months is not included in the statistics on immigration, and secondly there is no statistical survey on the people who leave Britain, so all figures on migration to Britain are vague.
My research led me to believe that the estimated number of migrants leaving Britain is about half the number arriving, and even Migration Watch has no sure idea on this. But every year, Britain's population increases by hundreds of thousands.
This and another online article: Unemployment in Briitain, both have links to official statistics offices on work and immigration, and quote sources.
