Passing variable to partial inside partial

In the view.html.erb:

<%= render @posts %>

In each _post.html.erb:

<%= render 'shared/block', blockedcallsign: post.callsign %>

In each _block.html.erb:

<%= button_to blockrelationships_path, class: 'btn btn-default btn-xs',
                        params: { 
                            blocker_callsign: @callsign, 
                            blocked_callsign: @blockedcallsign
                        },
                        remote: true do %>
<% end %>

Looking at the server logs, the blocked_callsign parameter is blank. I'm not passing the variable to the partial correctly. What's wrong with the code?

EDIT

With blockedcallsign instead of @blockedcallsign in _block.html.erb:

<%= button_to blockrelationships_path, class: 'btn btn-default btn-xs',
                        params: { 
                            blocker_callsign: @callsign, 
                            blocked_callsign: blockedcallsign
                        },
                        remote: true do %>
<% end %>

and the following in _post.html.erb:

<%= render 'shared/block', locals: { blockedcallsign: post.callsign } %>

I get the error: undefined local variable or method 'blockedcallsign'.