It may be waterlogged

thanks, what should i do to relieve that? does it need moving?

Maybe dig it up, it is the right time of year, and put a generous amount of grit under the roots, then replace. The drainage will be improved. It will need an initial watering just to settle it.

there is already quite a lot of grit in this particular bed. Might the problem be something else?

Doesn't look like waterlogging to me, in fact, more like the opposite, though I'd ask, does it get a lot of light and sunlight in particular? These plants really don't like a lot of sun, they burn because the soil gets too dry; what they like is dappled shade and damp soil.

nope, its in a shady bed - i bought it especially for the location

Not weedkiller or bleach/patio cleaner fluid splash from the path?

If it is neither too much sun or too much water or too little of either then you are looking at some sort of infection. Choices are wide, fungus, virus or bacterial. All these can cause leaf spotting in almost any plant there is. Viruses are impossible to deal with so if it is one of then there is little one can do. Fungus is a bit easier, try using a systemic fungicide. Bacteria is hard for the amateur to deal with either. Trouble is there are no specific mentions of leaf troubles in Brunnera in any of my books.

Ditto, I've been checking too, Owdboggy - pretty sure its not viral, no torsion of the leaves and no yellow mottling. When you say its "constantly covered" Howee, does that mean all year? Is it worse now, in this picture? Do the leaves go completely brown and drop?

Try here, see if you can get any info our of this site!
http://myfolia.com/plantings/54941-brunnera-jack-frost-brunnera-macrophylla/care_instructions

Mine is the same, what is left of it, something has eaten it :(

thanks everyone, no its not anything chemical, dont believe in it! It has been worse since autumn, but is there all year round.