* Late 2008 or early 2009: Fine Gael frontbench member Alan Shatter is stopped at a garda night-time mandatory checkpoint in Pembroke Street in Dublin. He says he was unable to complete the breath test because he is asthmatic and was waved on.
* May 2012: Independent TD Mick Wallace is stopped at a traffic lights on Dublin's North Circular Road, while he was speaking on his mobile phone. Mr Wallace says he put down the mobile and apologised. The gardai let him off without issuing a fixed charge notice to him.
* September 2012: Justice Minister Alan Shatter is sent a copy of allegations by the two garda whistleblowers of widespread quashing of penalty points by gardai.
* November 2012: Mr Wallace raises the issue of penalty points being quashed in the Dail.
* December 2012: Independent TDs Mick Wallace, Luke 'Ming' Flanagan (right), Clare Daly and Joan Collins hold a press highlighting the penalty points dossier sent to them by the whistleblowers. Joan Collins later names several figures in the Dail using her privilege as a TD.
* March 12, 2013: Mr Flanagan admits that he had penalty points quashed twice
* March 13, 2013: Mr Wallace tells RTE's 'Morning Ireland' that Mr Flanagan had made a mistake - and that he should have taken the penalty points for using his mobile phone while driving.
* May 16, 2013:The long- awaited penalty points report is released. On foot of the report, a number of gardai face disciplinary action.
During a debate on the penalty points report on RTE's 'Prime Time', Mr Shatter claimed Mr Wallace was let off with a caution by gardai when he was stopped while driving on a mobile phone. Mr Wallace said he didn't remember any such incident.
* May 20, 2013: Mr Wallace said he eventually recalled the incident involving the gardai.
* May 21, 2013: Mr Shatter says the Garda Commissioner Martin Callinan gave him the information about Mr Wallace's incident, but continues to defend his actions and makes a kind of apology. "If Deputy Wallace feels that I did him some personal wrong by mentioning it, then I have no problem in saying I am sorry."
* May 23, 2013: Independent TD Mattie McGrath asks Tanaiste Eamon Gilmore about an incident involving Mr Shatter being stopped at a mandatory checkpoint, but failing to complete a breath test.
Mr Shatter confirms being stopped at a checkpoint, but failing to fully complete the breath test due to being asthmatic.
"I explained this to the garda. I also explained that I was on my way home from Dail Eireann and that I had consumed no alcohol of any nature that day."
* May 24, 2013: Fianna Fail tables a motion of no confidence in Mr Shatter. Taoiseach Enda Kenny and several Cabinet ministers jump to support their colleague, saying the Government will strongly defend Mr Shatter's record.