CARACAS - Venezuela kicks off the home stretch of its presidential election campaign on Thursday ahead of voting planned for the end of the month, where analysts and pollsters say incumbent President Nicolas Maduro may be on the back foot.

Opposition activists have regularly denounced what they call oppressive tactics by Maduro, a socialist seeking a third term, including imprisoning opposition members. Maduro on Monday said he had agreed to restart talks with the United States, although officials there have declined to confirm that.

The run-up to the campaign's official start on July 4 has been atypical, with the opposition building a substantial polling lead even after a court banned its leader Maria Corina Machado from running, forcing her coalition to rally behind a new candidate, Edmundo Gonzalez, a little-known former diplomat.

Campaigning ends on July 25, three days before the election.

The opposition has been forced to campaign mostly via social media and word of mouth as it finds itself starved of funds and access to state-run traditional media.

Yet Machado has still seized the spotlight by campaigning in several towns accompanied by hundreds of motorcyclists, a tactic so successful that Maduro has taken to holding similar events supported by teams of motorcycle-mounted stunt men.

With many among the OPEC member's electorate angry about declining living standards and a stagnant minimum wage, some analysts see the government struggling to overcome opinion polls that show the low profile Gonzalez holding a roughly 20-point lead over Maduro.

"Never before has the opposition enjoyed such a gap in a presidential election," said John Magdaleno, a political scientist and director of the Polity consulting group.

Still, there remain widespread doubts about whether the July 28 vote will be credible, due to moves including the revocation of an invitation to European Union election observers.

There are glimmers of hope for the opposition, which has urged the country's military to uphold the country's institutions.

Unlike the election in 2013 - the last time opposition politicians took part - when Maduro's side spent millions of dollars on merchandise and musical numbers to rally his faithful, the ruling Socialist Party is spending less, analysts say.

The reduced spending, which analysts said was part of a wider austerity effort meant to highlight the party's fight against soaring inflation, has also helped level the playing field with the opposition.

  - Reuters