European Council President Donald Tusk attends a summit between Arab league and European Union member states, in the Red Sea resort of Sharm el-Sheikh, Egypt, February 25, 2019. REUTERS/Mohamed Abd El Ghany

BRUSSELS (Reuters) - A long extension of Brexit talks between the EU and London means at least a year and would require Britain to hold elections to the European parliament in May, a senior EU official said on Thursday.

The chairman of European Union leaders Donald Tusk said on Thursday he would ask EU heads of state and government to be open to granting Britain a long extension of Brexit talks if London needs time to rethink its strategy of leaving the EU.