According to
Rhashan Stone's facebook page, City Hall will premiere on May 3rd, to coincide with the Mayoral elections in London.
The transmission date for Rhashan's debut screenplay has been changed to the 3rd May to coincide with the real life Mayoral Elections in London. "City Hall" stars Olivia Williams, Rhashan Stone, Martin Shaw and Lucy Punch.
source
City Hall is the story of Dorothy Green, the unconventional housewife who becomes London's first female Mayor. It was commissioned by Sky.