Muhyiddin Yassin, who was sacked as deouty prime minister by Najib last year, submitted the application for the Parti Pribumi Bersatu Malaysia, or United Malaysian People's Party.
Former prime minister Mahathir Mohamad, a trenchant critic of Najib, is expected to become the chairman, Muhyiddin's aides said.
Mahathir, who was premier for 22 years, quit Najib's ruling United Malays National Organisation (UMNO) in February, saying it had degenerated into an organisation whose sole purpose was to protect Najib.
Party officials said they were not sure how long it would take for their registration to be approved by authorities, who have the power to refuse to do so.
Muhyiddin had repeatedly supported mounting public calls for Najib to answer allegations that billions of dollars have gone missing from a state-owned fund which he founded, in complex overseas transactions that have never been fully explained.
The accusations include the revelation that Najib received USD 681 million in deposits to his personal bank accounts in 2013.
The US Justice Department filed lawsuits last month to seize assets including luxury real estate in Beverly Hills, New York and London, works by Monet and Van Gogh, and a Bombardier executive jet, saying they were purchased with money stolen from 1MDB.
The US filing accuses an individual it calls "Malaysian Official 1" -- an apparent thinly veiled reference to Najib -- of taking huge sums, along with Najib's stepson, a close family associate and other figures.
Ibrahim Suffian, head of independent polling firm Merdeka Centre, told AFP the new party "could well present a credible challenge" if it can work with the other opposition parties.
Leaders from across Malaysia's political spectrum, led by Mahathir, joined forces in March to call for Najib's resignation.
But the premier tightened his grip on power and has purged ruling-party critics, curbed investigations and cracked down on reporting of the financial scandal.
Analysts say Najib's position within UMNO seems secure. But the coalition dominated by the party, which has ruled since independence in 1957, lost the popular vote in the 2013 general election while winning a majority of seats.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
