OUTGOING Colombian President Gustavo Petro called on his supporters to protect his government’s social and economic reforms and resist any efforts by the incoming right-wing United States-backed administration to change the nation’s labour laws.

The left-wing leader accused Israel and the US of interfering in Colombia’s recent presidential election, in a lengthy speech on Monday that marked the nation’s Independence Day and that he said would be his last as the nation’s head of state.

President-elect Abelardo de la Espriella, a right-wing lawyer and dual US-Colombian citizen, who will be sworn in on August 7, has promised to cut government spending by up to 40 per cent and draft labour laws that will enable companies to hire employees on an hourly basis. 

Mr Petro doubled down on accusations of electoral fraud, saying he would soon provide evidence on how vote tallies were rigged with the help of software supplied by Israel. 

Colombia’s electoral authorities have dismissed allegations of fraud.

Mr Petro also urged his supporters to mobilise “by the millions” and organise strikes if the nation’s incoming government tries to change labour laws, which have increased overtime pay and made it harder for companies in Colombia to hire workers on short-term contracts.

He said: “We must exercise our opposition in the streets, and resist peacefully but in an overwhelming manner.”

Political tensions have increased in Colombia following the June 21 presidential election, which Mr de la Espriella was judged to have won by a small margin of 250,000 votes. 

The losing left-wing candidate, Ivan Cepeda, initially recognised the results, but later said that if Mr de la Espriella does not renounce his US citizenship, he will not acknowledge him as a legitimate head of state.

Mr de la Espriella previously ran a Florida law firm that represented high-profile clients, including former leaders of Colombian paramilitary groups and businessmen charged with money laundering.