hi welcome there is such a thing called weed. feed and moss killer sold in bags also if i remember it rightly phosphate of iron as well to kill moss.but what ever you decide to use you should wait until spring before doing it good luck and happy gardening.

Take one part hydrogen peroxide and nine parts water, place it in a spray bottle and apply it to the patches. Use this solution all up in your application and make a fresh one each time you see the need to apply.....this solution does not have a good shelf life. Repeat once a week until moss and fungus are gone. This is very safe to use around children and pets.

Moss & fungus are indicative of very wet & soggy ground conditions.

thank you for the answers , I think everyone has soggy ground right now in the north of England :)

When you say fungus are you sure that's what it is? If it is then ordinary lawn weedkillers won't affect it. However it might be lichen or one of the lawn diseases - can't tell without a better description or a photograph.

You would expect moss in this weather. If the lawn is always mossy it might need better drainage. if it is under trees or other shade you might need a different variety of grass developed for shady areas. If it's just become rather mossy because of the weather then as above just apply a lawn mosskiller from the Garden Centre in the spring, following the packet directions. (Read the packet - combined weed and feed weedkillers don't affect moss, just broad leaved weeds). But do be careful how you apply it as its very easy to burn the grass if you don't spread it very evenly. You will be shocked by the areas of black dead moss but don't panic.You can rake it out or hire equipment to do it. There may be a lot of bare patches afterwards which you can then reseed.

I have plenty here too. I like the green fuzzy moss.

big mushroom type fungus, 3 a the moment, the biggest about 6 inches diameter . the ground is saturated because we haven't had many dry days this month.
what would be the best method , trying to drain or trying to dry ?
thank you for answers so far , much appreciated

No need to treat the fungi then - they will disappear soon enough on their own. They may reappear next autumn but nothing to worry about - the main part is under the ground, a wide network of white threads which would be unaffected by weedkillers. They are just the fruiting bodies of a much bigger organism. If they offend you just pick them off but I'd leave them alone. Its the moss not the fungus that comes when the ground is too wet, but everyone's lawns are too wet just now so don't worry about drainage unless yours stays wet when the weather had been dry for a while.. Just be patient and wait until spring and hopefully things will sort themselves out then.

thank you Steragram