Ross took leave from Parliament earlier this month citing personal health issues as the motive.
Moments before Bridges spoke to media about the report today, Ross also took to Twitter to say the leader would attempt "to pin his leak inquiry on me".
"Some months ago I fell out with Simon," the MP for Botany said.
"I have internally been questioning leadership decisions he was making, and his personal poll ratings which show he is becoming more and more unlikeable in the public's eyes."
Ross also threatened to go public about claims around "unlawful activity" and Bridges election campaign and donations he received.
However, Bridges said allegations made by Ross today on Twitter were wrong and he was "lashing out".
He also rejected claims there were inconsistencies in relation to donations to the National Party.
Judith Collins also came out swinging against Ross and his Twitter tirade, calling it "pretty appalling".
"I would not put up with it if I was in his [Bridges] position."
She said Ross should have come forward sooner, given "every other member of the caucus has had their privacy breached," she said in reference to the PWC report.
Behind closed doors, the National Party caucus will meet to discuss the future Ross has with the party.
The leak inquiry
The National leader has previously said he did not believe Ross was the leaker and that he hoped to see him return to Parliament.
Bridges' travel and accommodation expenses for the June quarter were leaked to the media three days before they were publicly released on August 16.
National's deputy leader Paula Bennett has overseen the investigation, which was carried out by PwC.
Speaker Trevor Mallard commissioned his own secret inquiry into the leak of Simon Bridges' travel expenses after hearing that Bridges had been privately blaming the Speaker for the leak.
The inquiry by KPMG cleared him and Parliamentary Service staff who had access to the expenses document, according to a memo written by Parliamentary Service and released by Mallard.
It means there were two separate taxpayer-funded inquiries going on at the same time, one into the National Party MPs and staff, and one into Mallard and Parliamentary Service staff.
National commissioned the PwC inquiry after Mallard cancelled the official wider inquiry which was to have been conducted by former Solicitor-General Michael Heron QC.
Mallard cancelled the Heron inquiry after it was publicly revealed that he, Simon Bridges and MediaWorks had received a text from the leaker claiming to be a National MP, containing reference to matters relating to caucus meetings, and pleading for an inquiry not to be held on the grounds of mental health.
National MP Jami-Lee Ross went on leave a fortnight ago citing personal health issues, it was announced last week by Bridges and Bennett but Bridges said Ross was adamant he was not the leaker.
In a statement tonight, Speaker Trevor Mallard sought to make a "point of clarification" following the release of today's PwC report.
"I note that Paragraph 37 (o) of the PricewaterhouseCoopers (PwC) report indicates that Jami-Lee Ross communicated with me on the 23rd August.
"Mr Ross only communicated with me following a call that I made to him in the mistaken understanding that he was to be my contact on the leak inquiry while Paula Bennett was on leave.
"In fact, the contact was the Leader of the Opposition's Chief of Staff. Mr Ross was not able to take my initial call, and undertook to call me back. I accidentally cut him off and he called back a second time.
"I informed the office of the Leader of the Opposition of my error in this matter a few minutes later. I was not approached by either PwC or John Billington QC at any stage."
Mallard said he would make no further comment.
Leak saga timeline
August 13 - MediaWorks publishes a story based on Simon Bridges' leaked expenses
August 15 – Speaker Mallard agrees to hold inquiry
August 16 – Bridges, Mallard and Newshub receive anonymous text message allegedly from National MP pleading for inquiry to be called off on mental health grounds.
August 17 - Bridges talks to mental health experts and tells police about text on advice.
August 19 – Police tell Bridges they have identified and contacted the texter (wont name them) and that the person is getting support.
August 23 - Mallard names Michael Heron, QC, to conduct inquiry
August 24 – RNZ reveals that texts were sent the previous week to Bridges and Mallard, Ardern and other comment publicly.
August 24 - Mallard cancels Heron inquiry.
August 28 – On Mallard's request. Parliamentary Service starts an investigation into himself and PS staff who access to the travel expenses, using KPMG.
September 4 - Parliamentary Service reports that KPMG finds no evidence of any disclosure of the information to unauthorised parties.
October 2 - Bridges announces Ross to take several months leave to deal with personal health issues, says decision is "unrelated" to investigation into internal party leak.
