Refused Risk Assessment, constructive dismissal?

[Stronger1]

I have a relatively new health condition that means that I am quite restricted in my movement and going beyond that causes severe pain. It is not sufficient to be classed under disability law but aspects of it are recognised as debilitating. My employer was made aware of this 6 months ago. I requested a RA which was acknowledged and delayed due to covid. I subsequently went off sick, during which I requested OH involvement, with no response. During my absence management meeting a RA and OH assessment was agreed, but I was refused a phased return and had to go back to full duties, full time. My condition has deteriorated again, and it has taken several weeks for the OH report and RA to be carried out. The RA suggests that several major changes should be made.

I am on the verge of handing in my notice as my mental health is in tatters after months of no contact, and being expected to perform (including industry-wide unpaid overtime) at full pelt, whist suffering from increasing pain, with no RA or adjustments in place. I am awaiting my new contract before I hand in my notice (I have been open about the condition but new role should minimise risk naturally).

Do I have grounds for constructive dismissal?

[ULA]

To claim constructive dismissal you need to be an employee and have worked for your employer for at least 2 years.

Claiming constructive dismissal is quite hard to do and the onus will be on you to prove that your employer seriously breached your contract and that you resigned in response to it. In addition you will have to clearly demonstrate that you did everything you could to resolve the issue by, for example, going through the grievance procedure prior to resigning. In addition you must also show that your decision to terminate your employment was in response to the breach and not, for example, because you had been offered another job.