You can still object

OBJECTIONS: The 15^th May deadline reflects the minimum statutory  consultation period and the Council will in practice take account of representations submitted up until the Committee Date.
It would appear from the Web portal that the 15th May was a deadline for "Neighbours" (the few who were actually sent a letter about the planning application) 21 days from the date they sent out the letters. The 23rd May is 21 days since the press notice and lamp post note.
If you have not objected or know someone who intended to ,now you can. Each adult within the hosehold is allowed to object.