Venezuela's Supreme Court shot down on Monday one of the opposition's main tactics to oust socialist leader Nicolas Maduro with a ruling that any constitutional amendment to reduce the presidential term could not be retroactive.
Having won control of the legislature last year due to public ire over an economic crisis, the opposition coalition is seeking to remove Maduro via popular pressure, constitutional reform or a recall referendum.
However, government-leaning institutions are thwarting it at every turn: the National Election Council is dragging its feet on the referendum, and the Supreme Court is striking down measures passed by the opposition in parliament.
In its latest judgment, the court said that while modification of the six-year presidential term was viable in principle if approved in a referendum, "it cannot take effect retroactively or be applied immediately."
That decision, which came even before parliament had formally proposed an amendment, will add to opposition frustration at government stalling tactics and accusations that institutions are in the pocket of Maduro.
The 53-year-old former bus driver and long-serving foreign minister narrowly won election in 2013 to replace his mentor Hugo Chavez but his popularity has tumbled amid a recession.
Opposition leaders have called for a march to the election board on Wednesday to demand paperwork in the first step toward seeking the nearly 4 million signatures needed to trigger a recall referendum.
Venezuela's constitution allows elected officials to be recalled through such a vote halfway through their term.
Should Maduro lose a referendum and leave office this year, there would be a new presidential election, opening the door for the opposition. Were he to depart in the last two years of his term, the vice president, currently Socialist Party stalwart Aristobulo Isturiz, would take over.
"The recall referendum has to be this year. If it's not this year, there's no point," said opposition leader Henrique Capriles, who narrowly lost to Maduro in 2013, outlining plans for Wednesday's rally. "It's incredible that with so many problems in this country, we have to march to get a form ... We've been asking for two months."