Occupational health request advice needed

Good Morning 

I am looking to get some help and advice for my partner please regarding a letter she’s received today from her employer regarding a occupational health check

She has now been off work for 4 months in total in that time she has already had 2 home visits from HR to discuss her sickness etc etc 

Her last meeting was in January 2020 and we have today received a letter asking us to check over the meeting notes and also sign a form that gives them access to a occupational health request. The HR lady stated on the phone on Thursday after calling out of the blue to see if we had had the forms etc which we hadn’t She mentioned the occupational health request form and stated we actually don’t even need to get your permission as it’s already in your contract but we are being respectful by asking your permission 

My partner has been diagnosed with fibromyalgia and chronic pain syndrome along with depression and anxiety she’s still currently on the waiting list to see the chronic pain team at the hospital and has been for 4-5 months now but there is a 6 month + waiting list. Everything the doctor has prescribed hasn’t touched the pain and the doctor said he has given everything he is legally allowed to give hence why she needs to see the chronic pain team for stronger medication.

The above has all been explained in both meetings with HR and documented on the forms and nothing has changed she can’t go back to work due to the pain she most days dose not even get out of bed it’s that bad so to now receive this occupational request form to see what they can do to get her back into work it’s a joke as she needs this appointment with the chronic pain team until then nothing will change and even then it still might not work.

My partner also now has full entitlement to highest rates on PIP with the disabled badge etc since going sick we haven’t told her employer of this as of yet in case they just sack her etc would it be a good idea to mention this now ? Also can she refuse the occupational health request she doesn’t want them delving into her information especially when at the last meeting they said at 6 months they will be looking to sack her anyway she’s currently at 4 months now so really unsure on what to do 

any advice would be fantastic thank you all in advance