Help/advice needed - neighbour's Tom bullying our cats

[DinkyBabe]

Hi. We have had 2 rescue girl cats since June last year and with a lot of love and care they have settled into our home but are still a bit nervous at times. New neighbours arrived late last year and have brought 2 cats with them - 1 quiet little guy and a big Tom. Since then the Tom has been terrorising our cats - he hangs around the cat flap and has got into the house a couple of times. (We now lock the catflap at night and keep the girls in overnight). He has now started attacking our cats, biting one in the leg a couple of weeks ago and then biting the other in one leg and tearing the back of another leg (deep enough to require a ga and stitches) :( . Both our girls have become very nervous again now and we are also pretty nervous about letting them out.
We have used water to scare the Tom off but this doesn't seem to be working.
The neighbour has told us that the Tom is pretty feisty and attacked most of the cats where they used to live but she seems to find this quite amusing
If anyone has any ideas/advice as to how we should deal with this I would be very grateful.

(Sorry for the length of post and thanks for reading)

We have one of the cat flaps that recognises our cat's chip so that no other cats can get in. Other than that whenever I see the other cat I run out shouting like a looney to scare it off. Works a bit and makes me feel like I'm sticking up for my cat but really embarrasses my kids! I don't think there's much more you can do - we've had this situation since we moved to our house 10 years ago and the Tom that lived in our house was rehomed three doors down. He's getting old now and we're on our second cat - he seems to be more able to stick up for himself. Sorry not a huge help!

This is going to sound so mean ... so I hope I don't get madly flamed ... but in a similar situation I once set our cat flap to allow the aggressive tom in but it wouldn't allow him back out (three way locking cat flap). He found himself stuck in my hallway and totally at my mercy. I scared the bejesus out of him, terrified the poor thing (I know, I know, I hated myself when I was doing it, but he was badly beating up my poor cats on a regular basis ... I promise I did not physically hurt him, in any way). Anyway, then I let him out and he never, ever came back!

Extreme, I know. Ohhhh .... I still curl up inside with shame as I recall it all.

Thanks for the responses.
I'm not sure i fancy trapping the cat in my kitchen - he scares me and I'm pretty sure I would end up the worst off :).
I'll try shouting like a loony though when I'm squirting the water and try and make our garden an unpleasant place for it to be (without hurting it of course!)

Could you offer to pay to have it neutered ? If not tell them that you will be sending them the vets bills in future .

Apparently he's already been neutered! (He just seems to be a psycho cat). I think we may have to have a word about vet bills if it carries on happening - even though its my cats safety I'm bothered about its not great having to pay out £200 in a matter a weeks to have both cats treated.

Get a microchip cat flap Dinky. (I'm assuming your girls are chipped.) That way, they'll know they can have a safe place to run to. They're more expensive but many posters here swear by their effectiveness, in particular the Sureflap one.

Can cats have those calming collars that you can get for dogs , if so perhaps you could buy him one of them ?