Mauritanian opposition parties are studying the possibility of withdrawing their members from the parliament political sources confirmed on Monday.  The say the \'violation of the constitution\' is behind their decision. The opposition in Mauritania obtained legal advice to confirm the invalidity of the Mauritanian parliament’s decisions issued after the end of its term prompting  the opposition parties to considering withdrawing from the institution, the sources added. It’s worth mentioning that the Mauritanian parliament raised controversy among the political and legal circles after the ending of its term, without carrying out new elections on October, as the Mauritanian constitution provides.