Python Panel Slider Controlling Object material and World Sky Nodes at the same time?

Is there a way for a panel slider to control both an object’s material node and a world node at the same time?

I currently have the slider controlling the mix factor of a material that is assigned to a background plane and would like it to also control the mix factor of the world environment textures.

    obj = bpy.data.objects["Sky_Sunset"]

    mat = obj.active_material
    if not mat:
        layout.label("Create a material")
        return

    nodes = mat.node_tree.nodes

    # Define the specific node
    sky_colour = nodes["SkyMix"]


    layout.prop(sky_colour.inputs["Fac"], "default_value", text="Sky Colour")

I have tried a different direction in that I selected the Mix Node for the World and added a driver to the slider, I then selected the target to be the slider of the Mix Node on the Material, however on re-opening of the Blend file the connection breaks.

Below is my hatchet job at understanding the code but obviously it doesn’t work and I wouldn’t know if I am a million miles away from getting it right.

        #Vehicle Scene Sky setup
        obj = bpy.data.objects["Sky_Sunset"]
        
        world = bpy.types.NodeTree["Van World"]

        mat = obj.active_material
        if not mat:
            layout.label("Create a material")
            return
        
        worldmat = world.active_world
        
        
        

        nodes = mat.node_tree.nodes
        nodes2 = worldmat.node_tree.nodes 
        
        # Define the specific node
        sky_colour = nodes["SkyMix"]
        sky_colour_world = nodes2["WorldSkyMix"]

        layout.prop(sky_colour.inputs["Fac"], skycolour_world.inputs["Fac"], "default_value", text="Sky Colour (Sunset 0 - Blue Sky 1)")
        

Any help would be greatly appreciated.

Tom

Can’t you just use a regular driver?

Did you see my note about the Driver problem? Everytime I open the file the connection is broken.