To be running out of patience with MH issues of business partner?

[Broadshoulders]

Have name-changed for obvious reasons.
I run a fairly young business with 2 business partners. We employ a team of approx 10-15 staff and everyone works extremely hard, that is except for one of the partners.
Each partner has a different knowledge and skillset associated with the business.
This one partner worked well for a few months but was increasingly flaky and has now been away from work for several months with anxiety and depression with no signs of any improvement. They initially resisted any treatment but I believe are now getting something.
We have had to do all their work and are at the stage that we really need their specific skills or need to take on someone who has them to try to continue to grow the business

The absent partner has still been getting full pay and dividends etc.

I am despairing that they will ever improve. We have tried to suggest various options eg returning part-time but the partner does not want to know. I and the second working business partner have differing views: I feel that we probably need to be patient a little while longer, the other partner wants to start exploring options including removal of the absent partner from the business.

Are they being unreasonable?

And does anyone have experience of how likely it is this person will be able to resume joint running of a business even if they do return after more than 6 months away?
They don’t seem to feel any better at all after months and months at home. We are working so hard it is difficult to feel sympathetic indefinitely.

I think they're taking the piss, especially taking a full wage and dividend. In your position, I would want to take steps to remove them from the company directors.

Do you have any type of formal agreement or contract? I think as an owner they would still get dividend but not sure they would expect a wage, what does your sickness policy state about paying wages after x months?
Ultimately they can't expect to receive a full wage for ever when they are not working, and if they are taking no steps to return you need to take action sooner rather than later if you want to remove them because the more the business grows, the more they will walk away with. I'd think it wise to get legal advice on next steps though

I think you and other partner need to be on the same page as it sounds like the ill partner is going to be resistant to any changes. Which I understand, because it can't feel good to be letting the side down/unable to do your job. But they are hampering the business and taking the piss a bit, so you need to do something.

I'd look at all your options and then present them quite factually - this is the situation, we need X and you're not providing it, we get it but we have to take action so here are the options and this one is our preference.

Can you afford to take someone on to fulfil their role if you're no longer paying their wage (just dividends - i.e. they remain as effectively an investor)? Can you afford to buy them out and if so, does that have any larger repercussions (their industry connections, their relationship to you, replacing their skillset)? Can you wait for a specific point in time that it makes sense to call a decision - i.e. they've been in treatment for 3 months, or end of a particular work cycle, or a quiet summer period or whatever, which is the point at which you'll need them back or for the sake of the business you'll need to move to replace their workload if nothing else?

I have 3 business partners and we're very much 'we pick up the slack for each other when it's needed', but this is a lot more than that - and it's not just about them, it's about you and your staff as well.

Yes, we have articles of association and an employee handbook with sick pay policy but I don’t think this applies as they are not technically an employee.
Thanks for your thoughts. I agree we need legal advice as this is starting to feel quite uncomfortable and could become quite complicated.