KUALA LUMPUR, Malaysia — From appearing in an R&B music video and trolling social media to vilify the new government, former Malaysian Prime Minister Najib Razak has been combative before the start of his graft trial, linked to the multibillion-dollar looting of the 1MDB state investment fund that has battered the country's standing abroad.

The trial was to start Tuesday, but Najib's lawyers won a delay of proceedings on Monday.

Najib's lawyer, Farhan Read, said the Appeal Court allowed the delay pending an appeal over a technical issue that the defense says could impair the validity of the trial. No date has been set for the appeal hearing. Prosecutors couldn't immediately be reached for comment, but reportedly said it could delay the trial by up to two weeks.

Anger over the 1MDB scandal led to Najib's spectacular election defeat nine months ago. U.S. investigators say more than $4.5 billion was stolen from 1MDB by associates of Najib between 2009 and 2014 and the ill-gotten gains were laundered through layers of bank accounts in the U.S. and other countries to finance Hollywood films and buy hotels, a luxury yacht, art works, jewelry and other extravagances. Some $700 million from the fund that Najib set up for Malaysia's economic development allegedly landed in his own bank account.

One of only a few Southeast Asian leaders to be arraigned after losing office, Najib has denied any wrongdoing. He is charged with 42 counts of criminal breach of trust, graft, abuse of power and money laundering in one of Malaysia's biggest criminal trials. His wife Rosmah Mansor also has been charged with money laundering and tax evasion linked to 1MDB. She has pleaded not guilty and her trial has not been set.

Instead of lying low ahead of his trial, Najib has fought back with a political makeover on social media that aims to transform his image from an out-of-touch elitist to a leader for the working class.

A Malay-language catchphrase translating to "What's to be ashamed about, my boss?" was coined while he was campaigning in a by-election last month and has become his new rally cry. Expensive tailored suits have been replaced by hoodies and jeans. A picture Najib posted on social media showing himself posing on a Yamaha motorcycle with his new "'no-shame" meme resonated with many Malay youths disenchanted by Prime Minister Mahathir Mohamad's new government.

In another offbeat music video that he uploaded on social media, Najib slammed the new government as "liars" and crooned about the "slander and revenge" against him in a Malay-language rendition of the 1970's R&B soul hit "Kiss and Say Goodbye" by the American group, the Manhattans.

He posts a dozen messages daily on social media, mostly mocking the new government and its policies, and touching on the plight of the needy.

Last month while visiting vendors at a wet market, Najib jeered government leaders on Facebook: "Let the ministers sleep on this Saturday morning."

Bridget Welsh, political science professor at the John Cabot University in Rome, said Najib is seeking to tap into anger from those who were displaced politically and those disappointed by the new government.

"There will actually be two battles — that in the courtroom and that in the public — in which Najib has used a flush-funded social media machine to build support," said Welsh, a Southeast Asia expert. "He has fanned two sentiments — supposed political victimization and racial insecurity — stemming from the fact that Malay chauvinists do not have the same level of political power in the new government."

Najib's online campaign isn't likely to extend beyond his Malay political base but it could split Malaysia along racial lines, she said. Ethnic Malays makeup about 60 percent of Malaysia's 32 million people, followed by large Chinese and Indian minorities.

Despite his smiles and cool public persona, the patrician Najib — whose father and uncle were Malaysia's second and third prime ministers respectively — could face years in prison if convicted.

Once a towering figure in politics and literally beyond the law, Najib has fallen from grace swiftly since his historic electoral loss last May 9, which led to the first change of government since Malaysia's independence from Britain in 1957.

The new government soon after it took office reopened investigations into 1MDB that had been stifled under Najib. He and his wife were barred from leaving the country and grilled by anti-graft officials, and their properties were raided. Truckloads of luggage stashed with cash, jewelry and hundreds of expensive designer bags worth a staggering 1.1 billion ringgit ($270 million) were seized from their home and other properties.

The trials for both Najib and his wife will be closely watched but are expected to be long-lasting as defense lawyers could appeals up to the top court.