Thanks for the advice so far.

Possibly a light issue as it is facing North.

It does look like someone has sat on it but not while I have owned the property (only the last 18 months) and it is getting worse.

The fence idea could work but as I own the hedge it would mean fencing off part of my (already small) garden, so I'm reluctant to do this.

It seems to me that there is two varieties of hedge and the one at the rear is dominant and seems to be pushing over the front one. I imagine I could somehow cut the inside of the hedge to allow space for the hedge to be levelled, but it will naturally fall now. How would I correct this lean?

I'll add another picture later which may help.

Many thanks,

Will