Complex sentence: According to the BBC, Ealing Central and Acton is one of about 20 seats that could shape the outcome of the 2015 general election, for which it is 56th on the list of Labour target seats.
Split into simpler sentences: According to the BBC, Ealing Central and Acton will be a key seat in the 2015 general election. It is 56th on the list of Labour target seats.