Days before a crucial election in Brandenburg, the east German state surrounding Berlin, a new survey has indicated the far-right Alternative for Germany (AfD) has a slim lead over its rival. A poll released on Thursday by public broadcaster ZDF shows the AfD on 28%, ahead of the of the previously dominant centre-left Social Democratic Party (SPD) on 27%. According to the ZDF poll, the conservative Christian Democrats (CDU) would achieve 14%, ahead of the Sahra Wagenknecht Alliance, a new party which combines left-wing social policy with a hardline stance on migration, with 13% of the vote. Th…