Theresa May has echoed Donald Trump by throwing the UK’s weight behind the opposition leader in crisis-torn Venezuela.

Downing Street described last year’s election of Nicolas Maduro, which has plunged the oil-rich country into economic freefall, as “neither free nor fair”.

And the prime minister’s spokesman said: “We fully support the democratically-elected national assembly, with Juan Guaido as its president.”

Emmanuel Macron, the French president, did similar, saying he saluted the courage of the “hundreds of thousands” of Venezuelans, who were marching for freedom.

The comments come after Mr Trump recognised Mr Guaidó as interim leader and urged the military to intervene against Mr Maduro, the protégé of firebrand socialist Hugo Chavez.

Venezuela protests: thousands rally against government Show all 18 1 /18 Venezuela protests: thousands rally against government Venezuela protests: thousands rally against government Protesters clash with the Bolivarian National Police during a demonstration against the government of the Venezuela and president Nicolas Maduro in Caracas on 23 January 2019 EPA Venezuela protests: thousands rally against government Demonstrators cheer as Venezuela's National Assembly head Juan Guaido declares himself the country's "acting president" at a rally in Caracas AFP/Getty Images Venezuela protests: thousands rally against government Opposition supporters take part in a rally against Venezuelan President Nicolas Maduro's government REUTERS Venezuela protests: thousands rally against government Opposition supporters take part in a rally against Venezuelan President Nicolas Maduro's government in Caracas REUTERS Venezuela protests: thousands rally against government Juan Guaido, head of Venezuela's opposition-run congress, declares himself interim president of the nation until elections can be held during a rally in Caracas demanding leader Nicolas Maduro's resignation AP Venezuela protests: thousands rally against government Opposition supporters carry letters to form the word "Democracy" while taking part in a rally against Venezuelan President Nicolas Maduro's government REUTERS Venezuela protests: thousands rally against government Police watch over marching anti-government protesters in Caracas EPA Venezuela protests: thousands rally against government A vehicle is overturned as opposition demonstrators block a road during a protest against the Venezuelan government AFP/Getty Images Venezuela protests: thousands rally against government A National Police officer fires rubber bullets during a protest against Venezuelan President Nicolas Maduro's government in Caracas REUTERS Venezuela protests: thousands rally against government A demonstrator throws back a gas canister while clashing with security forces during a rally against Venezuelan President Nicolas Maduro's government in Caracas REUTERS Venezuela protests: thousands rally against government Security forces look on after clashing with opposition supporters participating in a rally against Venezuelan president Nicolas Maduro's government REUTERS Venezuela protests: thousands rally against government Demonstrators during a protest against the government of Nicolas Maduro at Plaza Altamira in Caracas Getty Images Venezuela protests: thousands rally against government Demonstrators during a protest against the government of Nicolas Maduro at Plaza Altamira in Caracas Getty Images Venezuela protests: thousands rally against government epa07313731 Opponents of Chavism demonstrate against the Government of President Nicolas Maduro in Caracas, Venezuela, 23 January 2019. Chavists and opponents are again demonstrating in the streets of the country to support or question the legitimacy of the head of state, which the Parliament and a large part of the international community do not recognize. EPA/CRISTIAN HERNANDEZ CRISTIAN HERNANDEZ EPA Venezuela protests: thousands rally against government Riot police clash with opposition demonstrators during a protest against the government of President Nicolas Maduro on the anniversary of the 1958 uprising that overthrew the military dictatorship, in Caracas on January 23, 2019. - Venezuela's National Assembly head Juan Guaido declared himself the country's "acting president" on Wednesday during a mass opposition rally against leader Nicolas Maduro. (Photo by YURI CORTEZ / AFP)YURI CORTEZ/AFP/Getty Images YURI CORTEZ AFP/Getty Images Venezuela protests: thousands rally against government The remains of a statue of Venezuela's late President Hugo Chavez is seen hanging from a pedestrian bridge after it was destroyed in San Felix, Venezuela REUTERS Venezuela protests: thousands rally against government Riot police on motorcycles clash with opposition demonstrators during protests in Caracas AFP/Getty Images Venezuela protests: thousands rally against government Supporters celebrate Juan Guaido declaration that he is Venezuelan president EPA

However, No 10 stopped short of the US president’s move of recognising Mr Guaidó as the president, saying: “The UK position is to recognise states rather than governments.”

Mr Maduro was sworn in for a second term this month after elections last May that were marred by an opposition boycott and widespread claims of vote-rigging.

But hyperinflation, power cuts and shortages of basic items have driven millions of people from the country.

At a rally on Wednesday, Mr Guaidó, who is the head of the opposition-controlled National Assembly, told the cheering crowd that protests would continue “until Venezuela is liberated”.

Mr Guaidó then raised his right hand and said: “I swear to formally assume the national executive powers as acting president," vowing to lead a transitional government and hold free elections.”

In an apparently coordinated statement, Mr Trump described Mr Maduro’s leadership as “illegitimate”, adding: “The people of Venezuela have courageously spoken out against Maduro and his regime and demanded freedom and the rule of law.”

He said he was not considering military action, but added that “all options are on the table” – and called on other nations to follow suit in supporting Mr Guaidó.

Asked about the crisis, the prime minister’s spokesman said: “The 2018 presidential election in Venezuela was neither free nor fair, so the regime’s basis for power is deeply flawed.

“We fully support the democratically-elected national assembly with Juan Guaidó as its president.”

The spokesman also criticised Caracas for expelling US diplomats, saying: “In relation to the United States, we think it’s totally unacceptable for Venezuela to cut off diplomatic ties.

“The solution to this crisis lies in working to find a peaceful and diplomatic solution not in expulsions.”

And, strongly backing Mr Guaidó, he added: “The Venezuela government needs to respect the authority of the national assembly.”

Later on Thursday, the foreign secretary Jeremy Hunt issued a statement echoing the comments from Downing Street, and said the UK does not regard Mr Maduro as the "legitimate leader" of Venezuela.

During a visit to Washington for talks with US vice president Mike Pence, Mr Hunt added: "We are extremely concerned about the situation in Venezuela, but it is clear that Nicholas Maduro is not the legitimate leader of Venezuela.

"The election on May 20 was deeply flawed; ballot boxes were stuffed, there were counting irregularities and the opposition was banned.

"This regime has done untold damage to the people of Venezuela, 10% of the population have left Venezuela such is the misery they are suffering.