In their role of making strategic planning decisions for London, the Mayor may occasionally take over an application, therefore becoming the local planning authority. In particular, the Mayor takes over urban development plans that would have significant effects that are likely to affect more than one London borough. If the Mayor is confirmed to be the planning authority, they must then hold a public hearing before deciding whether or not to grant planning permission. Public hearings are normally announced at least one week in advance. They are held in the Chamber at City Hall, unless otherwise advertised. At the hearings, people or organisations can apply to speak and express their opinion on the planning permission of the site. In the past, public hearings were held for the Wimbledon Greyhound Stadium and Hale Wharf and will shortly be held for the National Institute for Medical Research and Bishopsgate Goodsyard.