Overgrown weed hedge obstructing my access

The hedge behind my fence is unnecessary and doesn't even need to be there. It's tatty, full of thorns, thistles and bind weed and completely engulfs my fence, eating away at it. It trails into my garden making it look a mess and my child cannot use the end of our own space due to all the weeds and thistles coming through the fence into my garden. My fence is enough of a barrier between me and the backfield so please either remove it completely if you can't keep it trimmed, or trim it regularly so it doesn't erode my fence and enter my private space. It's now obstructing my gate so I cannot access my garden. This is a yearly issue and my fence is rotting because of it.