Plaid Cymru MS Cefin Campbell has written to the First Minister asking him to take "urgent action" to tackle the second homes crisis.
The newly-elected MS for Canolbarth a Gorllewin Cymru described the crisis as a "perfect example of a free market causing cultural destruction".
Campbell also said that it was important for villages not to become merely "holiday parks for the wealthy", adding that the status quo "can’t continue!"
Last Saturday, Campbell attended a demonstration against second homes on Pen Llŷn.
In 1991, Campbell founded the first Menter Iaith in Cwm Gwendraeth, following the success of the Urdd Eisteddfod in the area. Menter Iaith is a community-based organisation which aims to raise the profile of the Welsh language in specific communities.
Today there are twenty-four Mentrau Iaith located in all corners of the country.
In recent years, second homes have become an increasingly contentious issue due to their adverse effect on communities and the Welsh language.
Second homes now account for more than 5% of the total housing stock in four local authorities:
Gwynedd - 10.76%
Sir Benfro - 9.15%
Sir Fôn - 8.26%
Ceredigion - 5.91%