Venezuela's fractured opposition said Friday it planned to drop competing agendas to unify behind a single candidate in the 2018 presidential elections in which leader Nicolas Maduro is seeking a new mandate.

"We promise to boost our unity... and will proceed with selecting a single candidate," the main grouping, the Democratic Unity Roundtable (MUD) coalition, said in a statement.

The coalition did not specify how it would choose its rival to Maduro. But on December 12, opposition lawmaker Luis Florido suggested consultations between the parties on holding primaries.

The division in the opposition coalition have given Maduro a clear path to holding on to power, despite broad unpopularity and deep societal malaise over scarce food and medicine as the once-rich oil-producing nation teeters on the brink of default.

By sidelining the opposition, Maduro has seen his loyalists win gubernatorial and municipal elections in October and December.

The cracks in the opposition were on display in talks it is holding with Maduro's government in the Dominican Republic aimed and finding some way to mitigate the country's crisis.

Some elements in the opposition view the dialogue to be a "betrayal" given protests demanding the Socialist president step down that took place between April and July, resulting in 125 deaths.

Venezuela's presidential election is scheduled to be held in late 2018, but the opposition and some analysts predict they could be brought forward to early next year.

"Maduro is going to push the strategy of bringing the elections forward as much as possible to avoid a regrouping of the opposition," said one electoral expert, Eugenio Martinez.