Linq Query Nested select + distinct

I'm having a really hard time converting this query to LINQ.

select fk, count(*)
from (
    select distinct fk, attribute1, attribute2
    from table
) a
group by fk
having count(*) > X

I need each distinct combination of fk, attr1, attr2 grouped by fk only where count is bigger than x (parameter).

Any ideas?