Help with disease/ailment identification

Hi, can anyone please identify the issue with this plant......been healthy and thriving for several years but started showing signs of 'ill health' this Spring and progressively worsening ever since. What needs to be done?
Thanks

 

Plant problems are not my forte.
It looks to me like an Iris.
Difficult to tell without flowers.
I think it has rust.
I suspect the horrid wet summer has made it worse.
This RHS link gives advise on id and treatment.
Good luck.

http://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=686

 

Yep, Rust

 

Thanks for the link Silver Surfer..........and the Rust confirmations John/Pete. I'll cut back the worst affected leaves and apply an appropriate fungicide as per the RHS advice.