I don't think there is any answer to slugs. You could make sure you attract the birds as thrushes and blackbirds will eat them, as will hedgehogs. A mulch will only give them a place to hide so probably the best thing is to go out at night with a torch and assassinate them! Salt is good or, if you aren't squeamish, you can squash them.

There are slug pellets, of course, but though I have a large slug problem too I refuse to use them because the birds will also get poisoned once they eat the slugs.

Hi Doranjo - for the last couple of years I have been asking that question and going out at night with a torch. Ugg! But I did find the answer was as Arbuthnot says. Its birds. In particular blackbirds (thrushes if you have them but we don't). All winter and spring we were out with the meal worms (no common or garden food for those birds) and they rewarded us with checking out the garden every time they came down. Only a couple of birds but it has done the trick. Only normal quantities of slugs now. I suspect they don't eat the very big ones (too much slime) but they eat loads of little ones and that has solved the problem. Hope this helps because it is dreadful when you get a big overgrowth.

I'd use slug pellets, frankly - the RSPB research indicates that birds are not poisoned by slug pellets, even if they consume a slug or three that's been poisoned by them. It was a surprise to me to learn that... but it is the case.

Thanks for all your comments, like Arbuthnot I am reluctant to use slug pellets and unfortunately Angela at 2, my slugs are jumbo. Thanks Bamboo I might have to look into slug pellets but it will be a last resort.
In the meantime I will continue slugging at night with a torch and putting out beer pots (the local foxes have taken a liking to marinated slugs), they also like the beer. We used to have thrushes, maybe still do but I haven't seen any signs of then recently. I am contemplating digging a small trench around my veg patch, lining it and filling it with salt water! that's desperation for you :)