By Jessica Frank-Keyes Londoners cast their ballots on Thursday in the mayoral election as Sadiq Khan and Susan Hall competed to become the city’s mayor for the next four years. Yesterday ballots were verified, which means checking that all ballots are accounted for and are in the correct ballot boxes, and turnout figures were revealed across the boroughs. Today, vote counting is now underway at venues across London with a declaration expected later on Saturday. Votes for the constituency and London-wide assembly members will also be counted and results declared alongside the mayoral result. W…