UPDATE: Patrick Brown has resigned as leader of the Ontario PC Party. Read it here.

Ontario Progressive Conservative Leader Patrick Brown denied allegations of sexual misconduct at an unexpected news conference at the provincial legislature on Wednesday night, calling them "categorically untrue."

The conference came just ahead of a CTV News report detailing allegations by two women dating back to when Brown was a federal MP.

CBC News has not spoken with the complainants.

In an appearance only about a minute long, a visibly distressed Brown said he'd learned about the allegations a couple of hours earlier.

"I want to say: These allegations are false. Every one of them," he said. "I will defend myself as hard as I can, with all the means at my disposal."

"I know that the court of public opinion moves fast. I have instructed my attorneys to ensure that these allegations are addressed where they should be: in a court of law."

Ontario will go to the polls on June 7, with the Tories looking to unseat Liberal Premier Kathleen Wynne.

Senior staff quit

Moments after the news conference, several of Brown's staffers including his campaign manager, chief of staff and deputy manager announced their resignations.

"Earlier today, all three of us became aware of allegations about Patrick Brown. After speaking with him, our advice was that he should resign as PC Party leader. He did not accept that advice," Andrew Boddington, Alykhan Velshi and Dan Robertson said in a joint statement.

"We have therefore resigned our positions."

Brown's press secretary also announced his resignation, and called for him to step down "immediately."

This evening I learned of allegations against Patrick Brown. As a result, it is in the best interest of the PC Party that he step down immediately. <br><br>As he has chosen to follow a different route, I am resigning as the PC Party Press Secretary. —@nickbergamini

The leader of Ontario's New Democratic Party, Andrea Horwath, echoed that call, saying: "Patrick Brown must resign, immediately."

"I'm disgusted and disturbed by these sexual misconduct allegations," she said in a statement.

"He deserves his day in court, but no person can lead a political party in this province with allegations like these hanging over his head."

Not long afterward, Wynne released a statement, saying coming forward was a "difficult and brave thing to do."

It's a difficult and brave thing to do to come forward in the way these young women have done tonight. My government and I have been clear on the issue of sexual harassment and assault. In fact our policy and our ad were called "It's Never Okay". —@Kathleen_Wynne

Federal Tory Leader Andrew Scheer said allegations are "extremely serious" and "should be investigated fully."

"Sexual misconduct, and sexual harassment have no place in Canadian society, especially within our political system," Scheer said in a statement.

News of the allegations comes as the PCs appeared to be in a dead heat in the polls with the Liberals, if not edging them out with a slight lead.

With the election just months away, Brown had just released an 80-page campaign platform that he dubbed the People's Guarantee, in which he vowed not to run for a second term if he failed to implement five key promises including tax cuts, new funding for mental health, and a new Trust, Accountability and Integrity Act.

In a year-end interview with CBC News, provincial affairs reporter Mike Crawley, Brown took aim at Wynne's "politically corrupt" government.

During their 14 years in power, the Liberals "may not have broken criminal laws but they certainly have broken the lines of what I think most Ontario families would view as appropriate ethical conduct," Brown said.

On Wednesday night, reporters followed Brown as he hurried outside, asking him for further comment on the allegations.

"I will be at work tomorrow," he responded.