What is this and how hard can I cut it back?

g.shouksmith

I’m slowly returning my mum and dad’s garden to it’s former glory. I’ve unearthed this from among a load of overgrown evergreen shrubs. It’s quite pretty but has got very leggy. What is it and what’s the best way to get it back in shape? Flowers have now opened and are small, almost white stars. 

Loraine3

I think it's a Clematis, but someone else will know name and pruning group.

Hostafan1

My first thought was deutzia

Busy-Lizzie

I think it's a Deutzia too. You can prune it when it has finished flowering, usually cut about a third off the stems that have flowered, but it can stand being pruned a bit harder. Just don't leave it too late after lowering or it will have grown the new stems that will flower next year.

g.shouksmith

Thanks @Hostafan1 and @Busy-Lizzie. I think you’re right. Now that you’ve pointed me in the right direction, I’ve looked it up and it looks like a D purpurea kalmiiflora. I’ll give it a good hair cut after it’s finished flowering and hope it fills out next year.