CAIRO — Egypt’s main opposition coalition said Tuesday it will boycott upcoming parliamentary elections, a decision likely to push the country into a new round of political turmoil and worsen an already troubled economy.

The announcement by the liberal, secular National Salvation Front was made in a televised news conference just hours ahead of the start of a “national dialogue” convened by Islamist President Mohammed Morsi to produce recommendations on ensuring the “transparency” and “integrity” of the vote. The NSF said it was also boycotting the dialogue.

The decision to boycott the election, due to begin in April, is a bid by the opposition to undermine the legitimacy of the rule of Morsi and the Muslim Brotherhood, the fundamentalist Islamist group he hails from.

Opponents accuse the Brotherhood of monopolizing power, and the country has been embroiled in months of protests amid public anger that the Brotherhood has failed to resolve the nation’s woes or meet the hopes of the revolution that toppled Hosni Mubarak’s authoritarian regime in 2011.

But the opposition also runs a risk. It presented a united front in its decision, but some factions may break ranks to run candidates. There is also no guarantee that the public will rally behind its call to stay away from the polls – making turnout a key measure of support for the opposition and discontent with the Brotherhood.

The Brotherhood won around 50 percent of the lower house of parliament’s seats in elections in the winter of 2011-2012 that were contested by all sides. Other Islamists won another quarter of the seats, leaving liberal and secular lawmakers only a small portion. The chamber was later dissolved by court order.

The United States is pressing the opposition to reverse its boycott decision.