People participate in an opposition rally in Caracas, Venezuela Thomson Reuters CARACAS (Reuters) - Venezuela protesters marched through Caracas and cities across the country on Saturday, as the government's ban of Venezuela's top opposition leader from office breathed life into the disparate opposition and fueled the first sustained anti-government demonstrations since 2014.

Thousands of people, some carrying signs reading "No to dictatorship!" and "Capriles for President," took part in marches against the unpopular leftist government of President Nicolas Maduro.

Saturday's protests continued a week of unrest sparked by last week's Supreme Court decision in which it assumed the role of the opposition-led congress. The action was quickly overturned, but the global outcry it sparked galvanized the opposition.

As during recent demonstrations, authorities on Saturday closed a dozen subway stations across Caracas and set up check points on highways leading to the capital.

"The government is afraid. If it were not afraid, it would not close the streets. ... It would not disqualify Capriles," said 27-year-old lawyer Gikeissy Diaz, adding that half of her graduating class has left the country — as have many young people amid a crippling crisis — and that she is thinking of doing so, too.

Two-time presidential candidate and current Miranda state Governor Henrique Capriles, who was seen by many as the opposition's best chance in the presidential election scheduled for 2018, was banned Friday from holding political office for 15 years. The order cited "administrative irregularities" including breaking contracting laws and improper management of donations, according to a copy of the ban.

Venezuela has been pummeled by a brutal economic crisis that has millions skipping meals, unable to afford the soaring prices for basic goods and facing long lines for scarce products.

Government critics say the ban on Capriles is arbitrary and allows the ruling Socialist Party to sideline popular politicians without due process to perpetuate its nearly two-decade-long rule.

After a recall referendum against Maduro was quashed last year and amid fears that next year's presidential election will not be fair, opposition supporters say they have no option but to take to the street. But after years of marching many are cynical while others are too consumed with trying to find food.

Still, others have been motivated by the escalating political crisis and the opposition coalition putting on a more dynamic and coordinated front than usual.

"It's been two years since I've been out on the streets," said Richard Morton, a 43-year-old electrical engineer who said shortages make it tough to import medical equipment, as he prepared to march under Caracas' hot sun.

"I'm out today because I see people acting in solidarity and the lawmakers are backing us up more. Plus the economic situation is insufferable, no one can live here."

Oil-rich Venezuela is in the throes of what is thought to be a fourth straight year of recession, with roaring inflation and monthly wages stuck at a handful of dollars at the black market rate.

'Illegal' March

Venezuela’s powerful new Vice President Tareck El Aissami declared Saturday's march “illegal and unconstitutional,” because the opposition had not received official permission for it. Over the last few days, authorities accused the opposition — and Capriles in particular — of fomenting violence and bloodshed by leading increasingly intense protests against Maduro.

“They’re seeking a provocation, that will lead to violence,” El Aissami said on Friday, adding the march could block crucial services like ambulances.

The opposition says it is security forces who are unnecessarily violent. A 19-year-old man was shot dead in violence around protests on Thursday, and a police officer has been arrested.

Rights group Penal Forum says almost 100 people have also been arrested during protests in the last few days. The opposition says over 100 political activists have been jailed amid a wider crackdown on dissent.

Capriles’ case has echoes of that of former presidential hopeful Leopoldo Lopez, currently serving a 14-year jail sentence on charges of inciting 2014 anti-government protests.

In 2008, Lopez himself was banned from public office on corruption charges. He had been expected to fight for the presidency in 2012 but had to hand the baton over to Capriles, who lost against Hugo Chavez and then against Maduro the following year.

Lopez was arrested in 2014, at the start of months of nationwide unrest that ultimately killed more than 40 people. Those protests achieved little, leaving the opposition fractured and despondent.

(Additional reporting by Corina Pons in Caracas, Isaac Urrutia in Maracaibo, Anggy Polanco in San Cristobal, Maria Ramirez in Puerto Ordaz; Editing by Leslie Adler)