Anti-government protests have erupted in the capital Antananarivo
Several elements of the laws, including the revision of electoral lists and the length of campaigns, went “against the constitution”, according to a post on the court’s website.
The opposition had argued the new laws benefited incumbent President Hery Rajaonarimampianina and called for his resignation seven months ahead of polls on the Indian Ocean island.
It came a day after the country’s defence minister appealed to the warring political parties to reach an agreement, after anti-government protests erupted on April 21 in the capital Antananarivo.
On the first day of demonstrations two people were killed and at least 16 people wounded, with the police accused of firing real bullets at the crowd.
The large island, which has been beset by decades of political instability, is due to hold the election in late November or December.
Conditions for presidential candidature and the use of single ballots were also among the details that have been dropped, the statement said.
The opposition had alleged that the new laws could bar some candidates from standing in the presidential election.
Elected in 2013, Rajaonarimampianina has not yet announced whether he will stand for re-election.
But two former heads of state have already said they would contest: Marc Ravalomanana, who was president from 2002 to 2009, and Andry Rajoelina, who removed Ravalomanana during a coup.
Both were barred from running in 2013 and their parties have been involved in the demonstrations.
Representatives of both the president’s party and of the opposition had met on Wednesday to try to find a solution to the crisis, but to no avail.