We already know the 2014 European elections are likely to be moved to late May, and now the government has started consulting on delaying the planned early May 2014 local elections to be on the same day as the European Parliament elections.
That has become the pattern in recent cycles with the local elections in years with Euro elections being moved to coincide with them. It is very likely to happen again.
The consultation document is below and details of how to respond to it are here. (Aficionados of email disclaimers should read paragraph 17 of the document.)Consultation_Document_on_Moving_the_date_of_English_Local_Government_elections_in_2014_