The resignation of a Conservative city councillor in Winchester has triggered a by-election and temporarily left the party with no overall control.
Amber Tresahar stood down as ward member for Upper Meon Valley last week. The reason for her decision has not been made public.
Her departure leaves 22 Conservatives, 21 Liberal Democrats and one independent councillor at Winchester City Council.
The poll will be held on 20 September and residents have until 4 September to register to vote.
In May's local elections, the Liberal Democrats gained two seats, reducing the Conservative majority to one.