Cistern siphon needs replacing, can't find one to match.

[mishk55]

My cistern doesn't seem to fit any other type of siphon. Heres a picture of the one that's broken. The water slowly leaks into the toilet bowl and the cistern has to refill every 10-15 mins.
It seems to screw directly into the base of the cistern rather than into any plastic pipework (not sure if that's unusual). Does anybody recognise it or know where i could get a replacement? Or some replacemenet washers at least encase that's the problem.

http://s859.photobucket.com/albums/ab152/mishk55/?action=view&current=DSC00130.jpg

[steve the plumber]

Screwfix sell them, or most plumbers merchants.