Page last updated at 21:47 GMT, Sunday, 27 April 2008 22:47 UK Berliners have failed to back attempts to keep open the city's historic Tempelhof airport, according to early referendum results. Just over 21% of Berlin's 2.4m voters opposed plans to close the airport, but 25% were needed for the non-binding vote to be considered valid. The airport's backers had hoped a strong vote would persuade cit