Yes. Any payment made by your employer under your contract of employment will be taxable as earnings and this includes any pay received during the notice period and any notice pay received as a lump sum, known as a payment in lieu of notice (PILON).
The law on this changed in April 2018. Since that date, tax and national insurance must be deducted by your employer from all notice payments and payments in lieu of notice without exception, whatever the contract says.
Tax law is complicated and you should ask for professional advice.