Guest director, Michael Rosen, will be in conversation with journalist Polly Toynbee about his role in this year's event.
It's also expected that the entire programme of events will be revealed in advance for the first time.
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Tuesday's weather for the west of the region
Tuesday's weather for the east of the region
A further 85 buses are expected to arrive on Tuesday and Wednesday, with officials saying the entire operation will last at least a week.