Please can anyone advise how o rid slugs

If you want to be really organic, take a torch out at night and pick them up and dispose of them in some fashion. There are various organic slug treatments available, (Bayer Organic slug killer, Nemaslug killer, Vitax slug gone and so on) google for those, they're not as effective as metaldehyde slug pellets though.

Also, set up traps. Put short boards or yesterday's folded newspaper in the beds. Before dawn, the slugs crawl under them for shelter, and when you get up, you can pick up their "roof" and scoop them up with a trowel. It may take several days of that treatment to make a dent in the population, then it will need to be repeated once a week to maintain.

egg shell around your plants,sharp stones or tons of slug pellets,as i do its what you find works

I have a similar problem snails and slugs all the time especially in the shady parts of garden,all the usual remedies only partially work,try covering around the plants with sharp gravel and grit( and grit sand as a base layer on after watering) genrously thats what I am trying now,it also acts as a mulch.

Yes. The sharp sand/grit trick around your plants is a good idea. I put rings of them around vulnerable plants such as Hostas which slugs love. Outside this barrier I also sprinkle a few slug pellets around it and this double-fisted approach does seem to work. You see numerous snail trails around these barriers but the plants stay untouched.