Mushrooms growing in bathroom due to significant mould - what next

As title says, mould problem in my bathroom has got so bad there are now mushrooms growing in the shower cubicle.

I moved in to a flat 4 months ago and reported via email issues with mould in the bathroom, along with a whole host of other issues (including no smoke alarm). Only one issue has been resolved (the smoke alarm), and this is due to the landlord "having cash flow issues" (property manager told me this via email).

I reported this via email to property manager on 25th June, they came to carry out an assessment this Monday 6th June, I am yet to hear back from them.

Needless to say I'm very concerned about the impact on my health from this. I've spent significant time chasing up the property manager to sort out these issues - the smoke alarm only got installed after I called the London Fire Brigade who then called the property manager themselves and threatened that if they don't install one then the landlord will be fined up to £5k and at risk of losing their license to let. I have limited confidence that the mould will be resolved in a timely manner.

My question is - how long until I escalate this further, and what can do to get my voice heard?