Lawyers for Nazir Afzal, whose older brother Umar died in April, have submitted a 225-page dossier to the Crown Prosecution Service (CPS).
He claims that investigations by his solicitors have uncovered new evidence.
Mr Afzal wants the CPS to prosecute the top Tory adviser for the 260 mile trip to Durham with his wife and son during the height of lockdown.
A Mirror and Guardian investigation revealed the couple’s rule-breaking journey to Mr Cummings parent’s home.
The two-week absence from the family’s London home included a day-trip to Barnard Castle which Mr Cummings claimed was to test his eyesight for the drive back down south.
Mr Johnson’s top advisor has always insisted he had acted within the spirit and letter of the rules.
He said: “The rules make clear that when dealing with small children, there can be exceptional circumstances and I think that was exceptional circumstances.”
The CPS will usually bring a prosecution if the legal criteria for doing so – known as the CPS ‘Full Code Test’ – is satisfied.
Mr Afzal, who was the CPS’ Chief Prosecutor for the North West between 2011 and 2015, said that the handling of the incident has created the perception “that the law isn’t being applied equally and the poorest, most vulnerable and least powerful of our citizens are those that suffer”.
In the submissions, Mr Afzal’s lawyers claim eye witness accounts and the explanations given show Mr Cummings was responsible for six breaches of Covid regulations.
The submission claims that Mr Cummings statement in the Downing Street garden is “wholly inconsistent with accounts of his conduct at that time obtained from eye-witnesses”.
Mr Afzal’s submission also calls for the police to carry out more investigatory work to obtain licence plate tracking, mobile phone and CCTV records to more firmly establish the sequence of events around the trip.
Mr Afzal said: “My one objective was to try to get to the truth.
“The police investigation thus far has been cursory and incomplete.”
A No10 spokesperson said: “The Prime Minister has said he believes Mr Cummings behaved reasonably and he considers the matter closed.
“Durham Constabulary have made clear they are not taking any further action against Mr Cummings and that by locating himself at his father’s premises he did not breach the regulations.”