Suella Braverman has accused the press regulator of being "blind to the truth" after it refused to apologise for criticising comments over Pakistani grooming gangs she made when she was home secretary.
Mrs Braverman wrote to the Independent Press Standards Organisation (Ipso) to demand a retraction of its 2023 ruling that she made "misleading" claims in an opinion piece that "almost all" child grooming gangs were British-Pakistani men.
In June the Casey Report into grooming gangs found that "disproportionate numbers" of men from Asian and Pakistani backgrounds were among the perpetrators, which Mrs Braverman believes vindicated her position.
But Ipso chairman Lord Faulks has written to her to say that he still believes "the decision is sound and does not conflict with the findings of Baroness Casey's audit".
Mrs Braverman said Ipso's position was "an outrage".
The row began after Mrs Braverman wrote an article for the Mail on Sunday in which she said the criminals responsible for the "grooming gangs phenomenon" were "groups of men, almost all British-Pakistani, who hold cultural attitudes completely incompatible with British values".
In her report, Baroness Casey found that police and council leaders covered up the scale of Asian grooming gangs because they feared being called racist.
But Lord Faulks argued that Baroness Casey's report emphasised that ethnicity is not recorded for two thirds of perpetrators, and that the Asian and Pakistani ethnicity of large numbers of gangs in the north-west was "not representative of a national picture".
Ipso made its original ruling after receiving a complaint from the Centre for Media Monitoring, part of the Muslim Council of Britain. The regulator said in 2023 it was wrong to make a "direct link between the identified ethnic group and a particular form of offending" where this did not specifically refer to abuse cases in Rotherham, Rochdale and Telford.
On Monday, Mrs Braverman said: "Ipso refusing to apologise for their judgement is an outrage to the victims of Pakistani grooming gangs and a denial of justice to the victims. The establishment is neglectfully blind to the truth.
"That's why I am proud of my record as home secretary. I set up the Grooming Gangs Task Force, which has led to over 1,000 arrests and saved thousands of future victims.
"By refusing to retract their judgement, Ipso have refused to accept the truth, that the systemic abuse and rape of white working class English girls was facilitated by an establishment and political class that believed the lie that diversity is our strength.
"Ipso's intransigence is a wilful denial of justice. Enough is enough. We must protect our women and girls. This cover up must end."
Ipso has faced a number of controversies in recent months. In April senior MPs expressed concern that free speech was being undermined by the watchdog, after it issued a reprimand over a report that quoted remarks made in Parliament.
In the same month Ipso was criticised for ruling that Palestinian prisoners in Israel could be called "hostages", even though the BBC, which is covered by a different regulator, was forced to make a correction when it used the same phrase.