George and Lynne are in a hot air balloon. George asks Lynne why they have gone up in a hot air balloon on election day. Lynne replies that it is because they are floating voters.
On first glance it seems that George and Lynne are the only people in the hot air balloon. Due to this it would be that either George or Lynne are experienced hot air balloon riders, because you would expect that an instructor or controller would be in the basket with them. However there does seem to be a pale figure behind Lynne. He is likely to be the controller and hires out his balloon to members of the public.
George and Lynne are going up in the balloon during the day so both they and the balloon man have time to get to the polling booth which will be open until 10pm. If this is taking place outside the Wimbledon area then we have to presume that George and Lynne have registered and voted by post. The balloon man will give his last balloon ride to finish at 7pm so he can have time to vote.
Lynne claims that both she and George are floating voters. It would appear that Lynne doesn't understand the term and believes it has something to do with literally being in the air. Even if she does understand, it bears no relevance on this election. This must be 1983. At this time, Wimbledon was a Conservative safe seat since 1950, and wouldn't swing to Labour until 1997. Perhaps this is why they have gone on a little trip. They know full well that their vote wouldn't make a difference in their constituency and so have decided to make use of the day to do something that they've been wanting to do for a long time.