London Underground is today accused of an appalling security blunder for allowing Abu Hamza's son to work on the network. Mohammed Kamel Mostafa, 25, from Wembley - a convicted terrorist - was given a security pass and access to restricted areas. He worked as a labourer at nights and weekends for a sub-contractor despite having spent three years in a Yemen jail for plotting to blow up British tourists. His father is serving seven years for inciting murder and racial hatred at London mosques. Labour MP Andrew Dismore said today of Mostafa: "It beggars belief. It wasn't like he was...