The Conservative is set to be suspended from Parliament for one day at the recommendation of a standards investigation which also ordered him to say sorry over the "insincere" apology he gave last year.
Mr Kawczynski had initially been asked to apologise when a standards committee ruled that he had acted in a "threatening and intimidating manner" towards parliamentary staff after drinking a "significant" amount of alcohol. It came as he was unable to connect to a virtual meeting during lockdown in April 2020.
Today the MP for Shrewsbury and Atcham told the House of Commons: "I sincerely apologise for my conduct which led to this investigation. I acknowledge that in speaking to journalists and on the radio I undermined the apology I gave to the House on the 14th of June in 2021.
"I am sorry that my conduct will have have a further harmful effect on the complainants, and that it may have diminished public confidence in the process. I will be sending a written apology to the parliamentary commissioner for standards, the chair of the Independent Expert Panel, and the original complainants.
"I am conscious that my conduct may have merited suspension from the service of the House of Commons for a longer period, and appreciate the committee's consideration of the difficulties I was experiencing in my personal life at the time, and the mental health issues I explained to them.
"I accept that speaking out in the way I did to the media had a detrimental effect on the House's conduct policy by undermining the integrity of the complaints process, and I deeply regret my actions.
"I am committed to learn from the mistakes I have made and to work on my personal development, especially in my communication with others in every interaction that I have.
"I hope others will learn from my experience, and I would be happy to share what I have learned with others.
"The House has rightly worked hard to change its culture so that everyone who comes onto the estate or has any dealings with parliament feels safe from bullying or harrassment. I want to do everything I can to assist in that and I regret that my actions fell short.
The words of the apology were agreed in advance after he was investigated for giving a radio interview on the day of his apology last year where he admitted he was only saying sorry because he had "no alternative" and wanted to avoid further sanctions.
The actions resulted in the latest sanction, which will see MPs approve his suspension in a vote.
Following the release of the committee's findings Mr Kawczynski issued a lengthy statement where he apologised for commenting on the Commons disciplinary procedures which occurred at a time when he was in an "emotional and distressed state".
The MP wrote: "My comments to Radio Shropshire came at the end of a very difficult and painful period in my life which I now recognise was significantly affecting my mental health.
"A profoundly emotional and devastating family trauma in 2019, coupled with a series of work-related problems combined to affect my mental health in an unprecedented way.
"Issues such as the extraordinary polarisation and vilification during Brexit, constituency flooding in an overwhelmingly damaging and exceptional way plus the start of a national pandemic meant that I got to the stage that I was not going outside when I returned to Shrewsbury because of the abuse I was receiving in the street whenever I ventured out, even to just do some shopping".
In its report, the committee said Mr Kawczynski had been required to apologise "unequivocally" for the earlier breach.
"Although he says he was sincere by the time he made the apology to the House, he had that morning effectively undermined the sincerity of that apology by broadcasting the fact that he was making it because he was required to do so and he disagreed with the way the case had been conducted," the committee said.
"Mr Kawczynski also broke confidentiality requirements by speaking to Radio Shropshire and identifying complainants' job descriptions on nine occasions in his radio interview."
Mr Kawczynski was a parliamentary neighbour and ally of Owen Paterson, who quit last year as MP for North Shropshire after a botched attempt by Prime Minister Boris Johnson to get him off the hook when he was said to have broken rules banning paid lobbying by MPs.
Mr Paterson's seat has since swung to the Lib Dem Helen Morgan in a shock by-election result.
An investigation by Parliamentary Commissioner for Standards Kathryn Stone also found Mr Kawczynski breached confidentiality rules by identifying the complainants through their job titles.
In its report, the committee said Mr Kawczynski's conduct was particularly serious as it risked undermining the credibility of the independent complaints and grievances scheme for Commons staff which has only recently been established.
Normally it would merit a more serious sanction but the committee acknowledged the mitigating circumstances cited by the MP, including his commitment to work on his "attitude and behaviour".
It said: "We are persuaded that Mr Kawczynski has been making a sincere attempt to arrive at a better understanding of the roots of his poor behaviour and is genuinely committed to this personal 'journey' and to assisting others who may find themselves in the same situation as himself.
"Mr Kawczynski has demonstrated to us that he is contrite. He knows that he was foolish and wrong to speak to the journalists as he did.
"But his contrition does not detract from the fact that his actions caused significant damage to the reputation and integrity of the House of Commons as a whole."