CARACAS, Venezuela (AP) — A prominent Venezuelan politician appears to be breaking ranks with the opposition coalition by challenging leader Nicolas Maduro in the upcoming presidential election.

A campaign consultant for Henri Falcon says the ex-governor will declare his candidacy Tuesday.

Officials loyal to Maduro scheduled an early presidential election for April 22, but the opposition says it won't take part until the government takes steps to ensure the vote is fair.

Falcon's consultant Eduardo Semtei says the government decision to allow international election observers is among the concessions that justify a challenge to Maduro.

The overall coalition is demanding more extensive changes, including delaying the vote and lifting bans on major political parties.

Oil-rich Venezuela has been sinking deeper into a political and economic crisis marked by shortages of food and medicine.