A question about plumbing fixtures and fittings.

Newspaper

Probably some sort of tee-piece. Best bet might be take a picture of the problem to your local plumber's merchant.

you need a left handed washer, You'll get one in B&Q, just ask someone.

It obviously needs to be some sort of end cap with a hole in the middle, but I'm struggling to find the correct fitting online.

http://www.amazon.co.uk/Twin-Adaptor-Connect-appliances-waste/dp/B005CTSA4W

toolstation push fit socket plug??

Many thanks, Stow Judge.

That fitting is on the right line, sir, but not quite right.  It's a little hard to explain, but the smaller waste pipe from the kitchen sink drops straight down into the larger waste pipe leading to the main sewer.  It leaves a gap of an inch or so around the diameter of the smaller pipe which, unfortunately, has allowed a rat ingress to the house.

I'm assuming the appropriate piece would be called a 'reducing coupler' or something similar, but have been unable to find one online.

The smaller pipe is about two inches in diameter and the larger pipe approximately five inches.

block it up with silicone or plumbers mait

Wouldn't there be a risk of silicone or plumber's mate falling down into the larger pipe and blocking it?

depends how big the plumbers mate is

what about this on ebay 121098075041

Yes, sir!  That looks perfect.  Thank you very much indeed.

your welcome hope you get sorted