The leader of the movement, Shia cleric Muqtada al-Sadr, announced the boycott in a press conference on Saturday.
All negotiations with other blocs are suspended until an unspecified time and all members of the Sadrist Movement must not attend the session to elect the Iraqi president on Monday, February 7.
A majority of two-thirds, 220 out of 329 MPs, is required to elect the president.

Two main candidates for the presidency of Iraq are Barham Salih and Hoshyar Zebari from the PUK and the KDP.

The two parties are at odds over nominating a candidate for the post.

A senior member of the Kurdistan Democratic Party (KDP) announced that Hoshyar Zebari, a senior member of the party, was nominated for the Iraqi presidency after the Patriotic Union of Kurdistan (PUK) insisted that Barham Salih will be nominated for the post.
"We did not intend to go to the polls for the Iraqi presidential candidate with two candidates, and the candidacy of Zebari is not to pressure or gain votes from any movement or block, but it was a reaction to the PUK insistence on nominating Salih for the post," Majid Shingali was quoted as saying by the al-Maelomeh News Agency.
Shingali added: "The presidency is the share of the Kurds, not a specific party, and there should be changes to the post, because presidents after Jalal Talabani did not play a big role."
The senior KDP member also said: "The political tradition regarding the election of the Iraqi president will change. The gap among the Kurds occurred in 2018 and we have clear agreements and commitments at the current stage and the number of representatives supporting each candidate in the Iraqi parliament will decide.
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