KUALA LUMPUR, Malaysia - Former Malaysian Prime Minister Mahathir Mohamad accused the government on Monday of bribing ruling party members to defeat him in party polls, and warned that his "big mouth" won't stop criticizing the current leader and his family.

Former premier Mahathir Mohamed's, seen here, humiliating defeat in a grassroots party ballot shows he is finished as a force in Malaysian politics after waging a bitter anti-government campaign, analysts said. [AFP\File]

In some of his most combative comments since starting a one-man anti-government campaign about a year ago, Mahathir also challenged Prime Minister Abdullah Ahmad Badawi to resign.

"Either he changes or he steps down," Mahathir, 81, told reporters. Otherwise, "the only way they can stop me is to throw me in jail," said Mahathir, who gave up power in October 2003 after 22 years as prime minister.

Mahathir accuses Abdullah _ the man he hand-picked to lead Malaysia _ of mismanaging the country, compromising national integrity and honor, and allowing his son and son-in-law to benefit from government contracts.

Abdullah denies the charges, and the entire Cabinet has stood behind him. Their pleas to Mahathir, a revered elder statesman, to end the diatribe have been largely ignored and raised fears that it could split the ruling United Malays National Organization party.

Mahathir's credibility suffered a dramatic blow on Saturday when he failed to win election as one of seven delegates representing the Kubang Pasu district at UMNO's annual congress in November. Kubang Pasu is in Mahathir's home state, Kedah, and is considered his stronghold.

Mahathir's plan was to give a speech at the congress to take his fight into the heart of the ruling party.

Mahathir will still be invited to the congress as a former party president, but the right to give a speech is typically limited to current top office-bearers and delegates representing UMNO's nearly 200 local divisions.

Despite the election loss, "I am not going to stop exposing this government's misdeeds," Mahathir earlier told a few dozen supporters at his office. "You can try to shut me out but I have got a big mouth. I am going to use this big mouth."

Mahathir claimed he lost the election because party members in Kubang Pasu were bribed and persuaded by the government to vote against him. He said each delegate was given 200 ringgit (US$55; euro43) and a list of candidates they should vote for, but didn't offer any proof.

"I lost because of lies and bribery, but morally I have won. For this very small election the state government and the federal government mobilized forces that made it appear to be a presidential election," he said.

The government did not immediately respond to Mahathir's allegations.

"You should be proud of yourself because you have used the biggest sledgehammer to kill one single wee mosquito," he said.

"They will try to stay in power but one day truth will prevail. They will pay a price for converting the Malaysian government into a family government of ... Abdullah Ahmad Badawi," he said.

Mahathir's criticisms began last year, when he accused the government of not protecting the national car maker, which he had championed. He stepped up his attacks this year after Abdullah scrapped plans for a new bridge between Malaysia and Singapore, which Mahathir had proposed.

Mahathir has said if he isn't elected, UMNO leaders could claim his influence has dwindled and that his current opinions have failed to resonate with members.

Mahathir said he has no intention of coming back into politics.

"But I have a duty to correct things that are wrong and make sure this country goes on the right path and is not made use by anybody for their own personal or family interests.