Telemarketer - Call through ex clients list

We're a Virtual Assistant service provider in the UK, providing PA and marketing support on a monthly subscription basis. Most clients are small business owners (consultants, coaches, accountants, marketing agency owners etc) but also some corporate CEOs.

We have a list of clients who once had an account with us (i.e. ex clients), the vast majority of which left on very good terms. Often clients leave because of a change in their business, they struggled to find time to delegate work, or they didn't have the budget.

The list stretches back to 2018, so there are approx. 300 clients in there. We'd like to get back in touch with these clients to remind them we're here, see if anything has changed and, ultimately, see if they'd like to discuss re-engaging one of our Virtual Assistants to help them.

Some of these clients could be in new roles, their business might have grown / changed (creating a new need for a VA to help them) or they may have decided working on their own (without a VA) wasn't a good idea.

I am looking for someone to call through the list (and email, from a company email account). I can put together some pointers to follow.

You must be very comfortable making cold calls and be based in the UK.

For now this is a one-off, but we're a busy team and so it could turn into something longer term / more involved if this works well.