The effects of far-right riots across the UK could be felt “for months and years to come”, the justice secretary warned.
Shabana Mahmood made the comments in an Observer article as courts worked overtime to try rioters charged by police during the riots.
Right-wing violence erupted in towns and cities across the UK following the deaths of three girls in a knife attack in Southport on Monday 29 July.
False rumours were spread online that the suspects were asylum seekers who had come to the UK by boat.
The National Police Chiefs Council (NPCC) said on Saturday that a total of 779 people had been arrested in connection with the riots.
Of these, 349 have been charged.
Ms Mahmood said: “If further crime or violence occurs we will continue to deliver justice until the last perpetrator is languishing in any prison.
But do not be fooled: this challenge is made even harder to meet within the justice system we inherited from the Conservatives.”
Ms Mahmood said there was a “record backlog in the Crown courts” and prisons were “nearly overfull”.
“The impact of these unsettling days will be felt for months and years to come. They are making it harder for our justice system to rebuild,” she added.
In the wake of the riots, the Education Minister said that as part of a curriculum overhaul, pupils will be taught how to spot extremist content and fake news online.
Bridget Phillipson told the Telegraph that under the new plans children as young as five would be taught the critical thinking skills to spot misinformation online.
Subjects such as English, ICT and maths would be used to “arm” students against “lazy conspiracy theories”, she said.
Meanwhile, Stephen Parkinson, the Director of Public Prosecutions (CPS), told The Sunday Times that hundreds of violent rioters are due to appear in courts around the country in the coming days.
The paper also reported that the CPS is considering charging him with the more serious offence of rioting, which could carry a 10-year prison sentence.
Many of those charged so far have been charged with violent disorder, which carries a maximum prison sentence of five years.
But in some areas anti-racism protesters far outnumbered far-right demonstrators for a fourth consecutive day.
Thousands of anti-racism demonstrators gathered outside Reform UK headquarters in central London on Saturday, with one organiser accusing party leader Nigel Farage of spreading “dangerous rhetoric”.
The demonstration was organised by Stand Up to Racism, and organisers said the roughly 5,000 participants were a strong show of support for refugees and other minority groups who have been victims of recent violence.
A spokesman for Reform UK issued a statement condemning the demonstration. He said the company was not disclosing its location because its headquarters are not in London and that “radical left-wing activists have infiltrated our offices in recent years” endangering “the safety and health of our employees”.
A man was briefly removed from the march by police, but authorities said no arrests had been made.
The action in London came as 14 far-right and anti-immigration protesters were arrested after gathering in Newcastle on Saturday.
Northumbria Police said they were arrested on a number of charges, including possession of an offensive weapon, possession of class B drugs and failing to comply with some orders.
However, as of around 5pm on Saturday, there were no protesters in the city centre.
It comes as eviction orders come into force in Liverpool city centre. They also apply to parts of Everton, Kensington, Vauxhall and Kirkdale. Merseyside Police said they had been introduced “following disturbances”.
Meanwhile, a petrol bomb was thrown at a mosque in Northern Ireland. Police described the incident as racially motivated.