CAIRO - Egypt's national dialogue among the presidency, different political forces, opposition and national figures, began Tuesday evening to discuss ways of guaranteeing integrity of the upcoming parliamentary elections slated for April 22.

President Mohamed Morsi, who headed the dialogue, once again invited absent political forces to join in, stressing the significance of dialogue in such a critical stage of Egypt's transition to democracy.

"I still stress my invitation to all forces to join the dialogue... for the integrity and transparency of the upcoming parliamentary elections," Morsi said in his opening speech of the session.

The president reaffirmed that "the recommendations of those attending the session will be referred to the Supreme Election Commission for approval."

Earlier on Tuesday, Egypt's main opposition bloc the National Salvation Front decided to boycott the upcoming parliamentary elections and also not to take part in the national dialogue.

"We cannot run for parliamentary elections without a fair election law and an unbiased government," Sameh Ashour, leading NSF member and head of Lawyers Syndicate, told reporters at a news conference Tuesday, noting the decision was reached by consensus of NSF members.

"We also decided with consensus not to take part in the so- called national dialogue because the Egyptian people do not accept to join a dialogue with imposed title and agenda that have nothing to do with Egypt," Ashour added, insisting dialogue in this case would be "useless."

Representatives of political parties and movements, including the Muslim Brotherhood's Freedom and Justice Party (FJP), the Salafist al-Nour Party and al-Watan Party, the moderate Islamist al-Wasat Party, leftist Development and Reform Party and liberal Ghad al-Thawra Party and the National Conscience Front (NCS), participated in the dialogue.

Meanwhile, three Egyptian churches announced Tuesday not to take part in the dialogue, calling for a private meeting with the president.

"Active participation and intensive turnout in the upcoming elections will be the real guarantee for its integrity and transparency," said FJP leader Mohamed Saad al-Katatny during the dialogue.

"The people wouldn't allow forging their will again," al- Katatny added, referring to the last parliamentary elections under the rule of Hosni Mubarak.

"We would even recommend removing any party involved in the violation of election rules," he added, rejecting calls for delaying the elections.

The FJP chairman also called for "a media charter of honor" to guarantee its neutrality, noting media could be manipulated as a tool for directing voters.