<Ul> <Li> Post-referendum organisations </Li> </Ul> <Ul> <Li> Change Britain </Li> <Li> More United </Li> <Li> Open Britain </Li> </Ul> <Tr> <Td> Calls for second vote <Ul> <Li> European Union Withdrawal Agreement (Public Vote) Bill 2017 - 19 </Li> </Ul> <Ul> <Li> Organisations campaigning for a second vote via People's Vote </Li> </Ul> <Ul> <Li> Britain for Europe </Li> <Li> European Movement UK </Li> <Li> For our Future's Sake </Li> <Li> Healthier IN the EU </Li> <Li> Open Britain </Li> <Li> Our Future Our Choice </Li> <Li> Scientists for EU </Li> </Ul> <Ul> <Li> Other organisations campaigning for a second vote </Li> </Ul> <Ul> <Li> Best for Britain </Li> </Ul> <Ul> <Li> See also </Li> </Ul> <Ul> <Li> Opposition to Brexit in the United Kingdom </Li> </Ul> </Td> </Tr> <Ul> <Li> European Union Withdrawal Agreement (Public Vote) Bill 2017 - 19 </Li> </Ul>

When did great britain join the eu and why