On 20 December 2011, the Council of the Common Market of Mercosur issued Decision No. 39/11, allowing member states to temporarily increase their import tariffs above the Common External Tariff for imports from outside the Mercosur common market.
 
Member states can invoke this provision for up to 100 NCM tariff lines, for a maximum - but renewable - duration of twelve months.
 
The measure is effective immediately, and will cease to be in force on 31 December 2014.

Update

On 16 December 2014, the Council of the Common Market of Mercosur issued Decision No. 35/14 extending the present measure until 30 June 2015.

On 16 July 2015, the Council of the Common Market of Mercosur issued Decision No. 25/15 modifying the present regime (see related state act).