Ontario Premier Doug Ford defended his finance minister Wednesday, saying allegations of sexual misconduct against the veteran legislator referenced in a book by former Progressive Conservative leader Patrick Brown are nothing but a "disgusting smear campaign."

Ford threw his support behind Vic Fedeli in a series of tweets, calling him "honourable, ethical and decent" and denouncing the allegations in Brown's book as "lies."

Fedeli, meanwhile, called the allegations "categorically false and without any merit," and said he was prepared to take legal action.

Brown stepped down as party leader in January amid allegations of sexual misconduct he continuously denies, paving the way for Ford to succeed him and lead the Tories to a majority.

He announced shortly afterward that he would pen a tell-all book, then returned to politics this fall, winning the mayoral election in Brampton, Ont., northwest of Toronto.

In the book, Brown alleges Fedeli was accused of "inappropriate behaviour" by a party staffer in December of last year.

Brown, who was still party leader at that time, said the accusations "were not anything I could picture being consistent with Fedeli's character" but that he could not disregard them and told Fedeli he would look into the matter.

Brown alleges that when he spoke to the complainant, she asked that the matter go no further.

"I respected her wishes and certainly without her involvement an investigation would be less than productive," he wrote.

Brown further alleges that the woman was let go shortly after Fedeli was named interim party leader, but that she was kept on the legislative payroll.

Opposition legislators said that if anyone made such allegations against the finance minister, the premier should order an independent investigation and remove Fedeli from cabinet until it is concluded.

"If there is any truth to allegations that the Conservative government is protecting Mr. Fedeli by buying the silence of his victim, Ford needs to come clean with the people of Ontario," NDP deputy leader Sara Singh said in a statement.

In denying the allegations, Fedeli suggested Brown was using his book to carry out personal vendettas.

"Facts related to Mr. Brown's lack of credibility are well documented and on the public record, as are his motivations in using his book to pursue old grievances," he said in a statement.

"Throughout my career I have held myself to a high ethical standard in my interactions with others. There is no validity whatsoever to any of these allegations."