Symfony2 get route name without locale prefix

Question

I am trying to translate my website with JMSTtranslationBundle and Symfony2.7.

I am trying to make a language switcher. So i need to get the current route name and create new routes with it for other languages.

{% set route_params = app.request.attributes.get('_route_params') %}
{% set route_params = route_params|merge(app.request.query.all) %}
<ul>
    {% for culture in cultures %}
        {% set route_params = route_params|merge({'_locale': culture.id}) %}
        <li>
            <a href="{{ path(app.request.attributes.get('_route'), route_params) }}">
                {{ culture.name }}
            </a>
        </li>
    {% endfor %}
</ul>

The app.request.attributes.get('_route') should return the route name like 'homepage', but it return the route prefix by locale like 'en__RG__homepage'.

Because of this, the route created for each language is the same that the current.

It is possible to get the route name without this prefix?

---

EDIT

For example, my homepage route definition is :

homepage:
    pattern:  /
    defaults: { _controller: APPBundle:Default:index }

And in my jms config:

jms_i18n_routing:
    default_locale: en
    locales: [en, fr]
    strategy: prefix_except_default

So, routes are translate in routes.en.xliff and routes.fr.xliff