Income tax and deferred state pension query.
 

After three attempts to get the HMRC helpline to answer and just waiting in an endless queue perhaps someone with some Tax knowledge or a more "senior" member might be able to answer this for me.
Next year I will be claiming back my deferred state pension as a lump sum. I know I have to pay income tax on it.
My question is how is this tax deducted ?
Is it taken off at source as a one-off lump sum deduction and that's it, I receive the remains as a tax paid amount…
or
Is the tax deducted monthly via my PAYE code over a twelve month period after I have received the total lump sum ?

If anyone knows the correct answer it would be appreciated.
Thanks
Brian.