CAIRO (Reuters) - The leader of a key Egyptian Islamist party rejected on Sunday the choice of Social Democratic lawyer Ziad Bahaa el-Din as interim prime minister, saying the post should go to someone politically neutral.

Younes Makhyoun, leader of the ultra-conservative Salafist Nour party, told Reuters he also objected to plans to make leading liberal politician Mohamed ElBaradei vice-president in a proposed transitional administration following the overthrow of Muslim Brotherhood President Mohamed Mursi last week.

"Both are from the same party, the National Salvation Front, this is rejected. I fear it would be going from one exclusive approach to another," he said, referring to accusations that the Brotherhood tried to monopolize power.

Bahaa el-Din was approached after Nour rejected ElBaradei for the premiership on Saturday, causing confusion in the nascent transition process.

(Reporting by Tom Perry; Writing by Paul Taylor)