Assabah reports Munir has contacted the Royal Moroccan Football Federation (FRMF) to ask for their support in his petition to FIFA to allow him to play for Morocco.
The Barcelona forward, who is currently on loan at Alavés, has also visited FIFA officials in person to appeal that they "defend the rights of binational players".
Morocco have qualified for next year's World Cup in Russia.
Born to Moroccan parents in San Lorenzo del Escorial just north of Madrid, Munir represented Spain at youth level and made just one, brief appearance at full international level - in Spain's first Euro 2016 qualifier, against Macedonia on 8 September 2014. He came on a substitute on 77 minutes, replacing Koke in the 5-1 win.