The Philippines’ late kleptocratic President Ferdinand Marcos routinely rigged elections, imposed years of martial law and is believed to have had political opponents assassinated during a reign of more than 20 years that was only brought to an end in 1986 by a popular uprising.

Nevertheless, in the run-up to Monday’s elections, the dictator’s son, Senator Ferdinand Marcos Jr., known by the nickname Bongbong, was the favorite to win election to the country’s vice presidency. Now, as it looks like he will be pipped at the post by a ruling Liberal Party candidate, Bongbong is crying foul.

The latest results Thursday show Congresswoman Maria Leonor Robredo leading Bongbong by just over 200,000 votes, with a total 13.97 million, according to partial unofficial results from the Commission on Elections, collated by Philippine-based website Rappler. (A concurrent presidential vote has been claimed by tough-talking Davao City Mayor Rodrigo Duterte.)

Bongbong’s camp on Wednesday issued a statement raising concerns about “contradictions” and possible “irregularities” in the results.

The Senator’s team claims that he was ahead in all exit polls, and appeared to be winning in the “quick count” of preliminary results until about 9 p.m. on election night, when his “substantial lead in the votes began to erode.” Robredo’s vote began to rise shortly afterward, and Marcos linked that pattern to an allegation that a piece of computer code was entered into the election body’s server at around the same time.

Bongbong supporters have taken to social media and to the streets to allege the candidate was the victim of a fix. For his part, the Senator called for “calm and sobriety.” “While we await these official results, he appeals for vigilance so that, ultimately, whoever may be proclaimed as winners, the true voice of the Filipino people will prevail,” the statement said.

Marcos Sr. is believed to have stolen more than $10 billion from the country during his rule, of which only about $3.7 billion has been successfully recovered by an official commission set up after his ouster.

As well as remaining wealthy — several family members, including Bongbong are named in the Panama Papers leak of information about offshore companies — the Marcos clan is still a powerful political force in the Philippines. The former First Lady Imelda Marcos, who gained notoriety for her enormous collection of designer shoes and penchant for extravagant jewelry, is a Congresswoman from the dynastic stronghold of Ilocos Norte, where her daughter Imee Marcos is the governor.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Simon Lewis at simon_daniel.lewis@timeasia.com.