| Gaia Watch | This is a British organization. It describes itself as follows: Population growth is primarily caused by natural increase, that is, the excess of births over deaths. But in any particular region, migration will cause population growth when the amount of i |
| Immigration Concern | A U.K organization which is very critical of the current high immigration policy in Britain. It looks at the negative economic, environmental and cultural effects of that policy. |
| Migration Watch UK | Migrationwatch UK is an independent think tank which has no links to any political party or organisation. It is chaired by Sir Andrew Green, a former UK Ambassador to Saudi Arabia. "We have a distinguished Advisory Council from diverse ethnic and professi |
| Optimum Population Trust | A British Organisation carrying out research into optimum population size in relation to environmental sustainability, particularly in the UK. |
