Need to get one tomorrow. The only shops that I'll be anywhere near is Halfords but I can't find them on their website. Do they sell them?
They tend to only do them in huge packs. Screw fix sell them too.
Edit: they do them in smaller packs too [url= http://www.halfords.com/webapp/wcs/stores/servlet/ProductMobileDisplay?catalogId=10151&langId=-1&categoryId=310504&productId=156338&storeId=10001 ]link[/url]
Cut up an old inner tube
Use a ziptie. Make a loop, pass it over both "hooks" and pull it tight.
A bit of inner tube as a shim will help give it more grip on the bars too.
I've got one you can have. I'll leave it on the doorstep, pick it up whenever suits. NW Scotland.
I've got some....
But use a zip tie as mentioned
Shoelace or string in an emergency. 😉