Pakistani national applying for chinese tourist visa in UK

Yes, you can apply in UK.

But the chinese visa center told me I can't? I'm still trying to find what the correct policy is. Too much conflicting info....

Hi, you can apply in UK if you can provide the original and a copy of your permanent residence or work permit for UK which should be valid for at least half a year.

I'm afraid that is not correct. Or the centre is misguiding me. For tourist L I hv to go to Islamabad or apply business F using invitation of duly authorised unit. Can you help me find out how to get that please?

Maybe you are not eligible to travel individually. You can confirm this with the center if you need to travel in a group.
BTW, do you know anyone in China? friend or relatives? if yes, you can ask them for an invitation letter. Otherwise, you may need to find help from travel agencies or visa agencies.