Pension Lump Sum - Income or Capital?

First - the standard response appears to be to contact the IHT Team. I have already done so and they were not authorised to answer my question despite it being HMRC who would 'rule' on a the matter. I have placed a small amount of my SIPP into drawdown; let's say £20,000. ( I'll increase this in due course.) Of this I have to take £5,000 as the tax-free lump sum else I 'lose' this amount from the current allowance of ~£268K. The balance I take as monthly income taxed at the basic rate. The income I can legitimately gift to our sons as 'regular payments from income'. However what is unclear is whether the £5,000 would be considered income or capital. If the former then it too can be gifted as a 'regular payment from income. If the latter then it would be gifted as a potentially exempt transfer.

Hi,
Please refer to:
IHTM14250 - Lifetime transfers: conditions for normal out of income exemption: out of income
Thank you.