Former Umno deputy president Muhyiddin Yassin has joined forces with PKR to embark on a nationwide roadshow to explain the 1MDB scandal in simpler terms to the public.

In his first public appearance with PKR president Dr Wan Azizah Wan Ismail, Muhyiddin said they would focus their efforts on both urban and rural areas.

"I think if the 1MDB issue is not widely explained in simple language, the people would not know its effect and impact on the nation," the former deputy prime minister said.

The 1MDB scandal recently took a new turn after the United States Department of Justice alleged that US$3.5 billion had been siphoned out of the state investment firm.

Putrajaya, however, says there is no proof that any funds had been misappropriated.

Asked later if this cooperation meant he would join PKR, Muhyiddin said this was not an issue, and he would support PKR's initiative regardless of which party he is in.

Muhyiddin was sacked from Umno last month after criticising Umno president Najib Razak over the 1MDB scandal.

He is expected to be the head of a new party, made up of Umno rebels including former premier Dr Mahathir Mohamad.

Speaking on the 1MDB scandal, Muhyiddin said some ministers believe that the public are "dumb fools" who would accept stupid explanations.

"This is not right. Perhaps they are the ones who are not smart enough," he said.

PKR deputy president Azmin Ali concurred, saying Umno had an agenda to fool Malaysians when it came to 1MDB.

"This is not just a theft, this is a robbery," Azmin added.

He said the roadshow would begin soon, although no specifics were given at the press conference in Subang Jaya today.