Gap filling and vermin proofing around supply cables

Location: rural. Property: Converted 19th century chapel

Hello all, can anyone recommend the best way to fill  gaps around a bunch of internal electrical cables please? The cables go through a hole in the plasterboard ceiling as can be seen in the photo. The cables then run along a first floor joist and would be a hell of a job to get to from the top. In the past mice have gained access and made a nest in the void so I want to seal this route. A corner wall kitchen cabinet has been removed to gain access to the hole and will be going back once work has been done.  I'm guessing wire wool and copper mesh is not a good idea but what should I consider - expanding foam? Look forward to your thoughts. Thanks. Phil 

ps I realise the most important thing is to stop mice entering the house and I have sealed all the gaps externally as far as I can.

expanding foam should work - damp the surfaces very carefully first, it sticks far better to a damp surface.