Duma deputies Ilya Ponomaryov and Oksana Dmitriyeva from the A Just Russia party and Leonid Kalashnikov from the Communist Party were among those who attended a meeting last Tuesday with newly minted U.S. ambassador Michael McFaul.
"The ethics commission should look into this situation," Isaev said during a Duma session, Interfax reported.
The United Russia deputy called McFaul a "specialist on Orange Revolutions" and said his appointment to Moscow was no accident.
Isaev also accused American political scientists of proposing the white ribbons and flags that have become a symbol of the opposition.
Liberal Democratic Party leader Vladimir Zhirinovsky joined Isaev on Tuesday in his criticism of the Duma members who met with McFaul, saying they should have to give up their mandates, Interfax reported.