Is Work Permit Copies required for ILR

I am heading for my ILR in next 2-3 months time. I was going through the form. Section 9B(Page 12) states:
9B.Document(s) confirming that you have spent a continuous period of 5 years in the UK:
- either as a work permit holder throughout that period, or
- as a work permit holder most recently combined with previous permission as a work permit holder, highly skilled
migrant, self-employed lawyer, or as a writer, composer or artist.

Now my doubt is, do I have to submit all the WP copies with the application? I intially had WP, then WP from another company, then HSMP and now Tier 1. I have HO letter of HSMP and Tier 1 but for WP, my employer didn't gave it to me
Is it absolutely necessary to submit the same?

don't bother about that if you have your latest and previous approval letters that would be fine

gg234 wrote:don't bother about that if you have your latest and previous approval letters that would be fine

Thanks mate. But do we have any such requirement.Couldn't find any concrete requirement in the guidance as well as in form.