In interview in Spain, businessman says he is in fear of contract killing and that he has new plan to topple President Sisi

The Egyptian whistleblower who prompted rare street protests against President Abdel Fatah al-Sisi from exile in Spain has said he is in a “state of shock” and feels a deep sense of personal responsibility for those jailed for answering his call to demonstrate. But he insisted his fight to topple Sisi will enter a new phase, claiming many junior officers in the army support his call for an end to corruption.

In an interview with the Guardian in Barcelona, where he says he lives in fear of a contract killing, Mohamed Ali, called for the US Congress to investigate how decades of US economic and military aid amounting to more than $70bn had been spent by the Egyptian state. “Trump has let Sisi steal as much of America’s money as he wants,” Ali said. “It is like a comedy film.”

Facebook Twitter Pinterest Mohamed Ali’s videos sparked protests last month. Photograph: YouTube

Ali’s unscripted handheld viral videos tormenting and ridiculing Sisi sparked an unusual outbreak of dissent last month in Egypt, where the regime has imposed strict economic austerity measures and 32.5% of people live below the poverty line. Small protests that took place over a number of evenings from 20 September were followed by a widespread crackdown in which more than 4,321 people have been arrested, according to rights group the Egyptian Commission for Rights and Freedoms.

A specific call from Ali for a million people to march on 27 September was stifled by authorities, who made clear they would use force to quell further demonstrations. He said he has stopped posting the videos for now – a tacit admission that his ability to bring people out onto the streets had died away.

He said he is now playing a role in uniting opposition groups, including liberals and the Muslim Brotherhood, into a new force ready to topple Sisi, who came to power in a coup in 2013 and has overseen a wholesale crackdown on freedom of speech and public dissent considered by observers to be the worst in Egypt’s modern history.

Ali said he had rejected calls by other opposition groups to join them in exile in Istanbul or Qatar, insisting he wants to stay in Spain.

Chain smoking and sometimes agitated as he prowls around the room in which he filmed his video monologues, Ali acknowledged that he is an accidental revolutionary.

The head of a large construction firm built up over 15 years, Ali raked in substantial profits from army contracts, building an ornate presidential palace for Sisi, intelligence headquarters, and unopened hotels owned by regime members. It was a shady world of patronage, bribes and open ended budgets. “With the army if you want a contract, you pay commission. If you do not pay a bribe under the table you do not get to do the jobs,” he said.

“Often there were open budgets. They did not mind how much you spent as long as it looked right.”

He also partnered with Egypt’s ministry of immigration to produce and star in the 2016 film The Other Land, a drama intended to dissuade Egyptians from attempting risky naval migration routes.

Facebook Twitter Pinterest A film poster for The Other Land, produced by and starring Ali. Photograph: Creativo Productions

Eventually he fell out with key military figures in the regime that disliked him and tried to block him from further business. The falling out, he claimed, left him being owed as much as 200m Egyptian pounds. He said that after ensuring his estranged wife and five children were out of the country, he was determined to expose the scams and waste.

A form of revenge by social media ensued. His regular Facebook denunciations of Sisi’s personal corruption have been shared millions of times, prompting street protests that momentarily appeared to shake the repressive regime.

The regime have described him as a drug addict, a traitor, a womaniser and member of the Muslim Brotherhood – the Sunni Islamist grouping that briefly ruled Egypt after the revolution that ousted Hosni Mubarak in 2011 – all of which he denies.

Many of Ali’s precise claims are unverifiable since he says he has no papers to prove the corruption. But Sisi himself has inadvertently given his tormentor credibility by clumsily confirming that he did indeed order palaces to be built, but that they were for the nation.

The son of a body builder with no university education, Ali does not pretend to be a political sophisticate. “I am in a state of shock. I do not understand anything. I did not expect this,” he said. “I had a few people following me on Facebook, thought a few people would watch, but it has gone viral and people in Egypt message me saying ‘you are our hope’.

“It is a load on me. There are people in prison and tortured. There are people in jail simply for possessing a phone that shows they watched one of my videos.”

After his call for further protests failed to meet a popular response, Ali said he was forced to change course. “Before I used to think I could do this alone. Now I speak to opposition politicians and I have more minds with me. No one can succeed by himself.” He claimed he had a secret plan that he will shortly unveil that “will surprise the whole world”.

Ali said Egypt’s beleaguered opposition has pressed him to explain what his vision for the country might be.

“I said: ‘I want Egypt to be like Europe, If you want to pray, you pray, if you want to go to the club, you go to the club. Be free. Do you have any problem with that ?’ They said no. The first rule of the constitution must be that the people decide through elections.”

Egypt’s presidential office did not respond to a request for comment, but Sisi has previously denied all allegations of wrongdoing and said he was “honest and faithful” to his people and the military.

Ali said he was neither a hypocrite nor motivated solely by revenge. “If I wanted my money I could have found a way to keep working for them and I would be one of the most important businessmen in Egypt.” He said he acted out of anger at the contrast between Sisi’s calls for austerity and his lavish lifestyle. “The country is on fire, and they are discussing the size of their kitchen,” he said.

“I do not take any decision without thinking very carefully and I planned my departure for many years, carefully taking my money out of the country.”

But for the moment he faces all the dilemmas of a political exile. “They have taken my nationality from me. My passport expires in a year and if I claim political asylum, I must stay here for a long time and not travel.” Regime loyalists in Egypt, he said, have put a price on his head, or threatened to sue him.

Ali claimed the Egyptian embassy in Madrid has invited him there with a promise that he will be repaid the money he says he is owed if he agrees to go quiet.

“I do not think they would kill me,” he said. “It would be catastrophic for them if they kill me in Europe, but I am scared of someone being paid to murder me”.