Every person at my school is there for the sole purpose of learning English, and the school has an "English Only" policy. Consequently, there aren't many opportunities for multi-lingualism which come my way. That said, here are some things I have done along with the school to advocate multi-lingualism.
We offer after school elective courses in Spanish, Portuguese, Russian and Korean for free to all current students, teachers and staff members. This fosters a culture of acceptance and multi-lingual understanding. Second, I exercise tolerance with students who need to speak their native language in order to help other students understand the more difficult points of a lesson. Dozens of times, I have sat silently as one of the stronger students took the time to explain to a weaker student an English concept or word using their mutual native language. I believe this understanding and willingness on my part shows them that I recognize that they are fighting a difficult battle, especially when they are only allowed to speak in their target language.
Something I haven't yet done but would very much like to do is to reach out to the refugee families who have been washing up on Ireland's shores. I've begun doing initial research and communication with relevant agencies regarding the best way to set up such a program. Next on my list are three local churches where I have been involved since coming to Ireland. I have also been speaking to some of my advanced and proficiency students to recruit them as teachers in this once per month program. I very much hope to be able to devote the time which will be required to accomplish this in the near future.
Finally, I believe the best way for me to advocate and support this culture is to learn additional languages myself. I am not studying one language feverishly, but I have made a consistent and conscious effort to learn Portuguese, Spanish, French and Russian over the past year.
Taking these small steps towards my students' L1 has paid dividends already, in the sense that they greatly appreciate my efforts to not only teach them but to be taught by them. I hope to increase my efforts in this regard over the next twelve months, once I am no longer in panic mode trying to keep up with a full time teaching schedule whilst pursuing a Master's degree in TESOL!