Two men who took part in a riot outside a hotel where asylum seekers where staying in Rotherham have been jailed, following the worst violent disorder the UK has seen in more than a decade.

Nathan Palmer, 29, and Niven Matthewman,19, have both been sentenced to two years and eight months imprisonment for being part of a violent mob that targeted a hotel housing asylum seekers.

At least 422 people in England and Wales have been charged in connection with the violent disorder, with some people facing multiple charges.

It comes as the government confirms emergency measures to ease prison overcrowding in England and Wales.

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Palmer, a self-employed tradesman, was said to have “commandeered” a police riot shield and joined the mob, while on licence for drug offences. He was part of a group of hundreds who targeted the Holiday Inn Express in Manvers, Rotherham, on 4 August.

Sheffield Crown Court heard Palmer’s custodial sentence would have an impact on the end-of-life care of his elderly grandmother, who has dementia and has been diagnosed with terminal cancer.

“What possessed you to participate in this crime can only be described as comprehensive stupidity,” Recorder of Sheffield Judge Jeremy Richardson KC told him.

Matthewman, also part of the same group of protesters, threw a chair at police and yelled “Yorkshire, Yorkshire”, after the hotel was set on fire.

Video footage also showed him draped in an England flag by a police van, which had a police constable, sergeant and police dog inside, being rocked by other rioters.

Mother-of-six Donna Conniff, 40, was sentenced to two years for violent disorder after she threw a brick and a rock at officers during a violent protest in Hartlepool.

She was identified from footage of the protest, which took place in the town on 31 July.

She was seen handing a brick to a child and encouraging him to throw it at the police

“Your behaviour and the behaviour of others around you was truly disgraceful,” Judge Francis Laird KC told her.

She will have to serve up to half of her 24 month sentence in custody before being released on licence.

David Notley, 67 has been jailed for 20 months after pleading guilty to violent disorder and causing religiously aggravated distress.

He was sentenced at Inner London Crown Court, after he shouted “you’re not English any more” at police officers during a demonstration on Whitehall.

Kelly Wildego, a 41-year-old mother, was given a four-month suspended sentence, after assaulting an emergency worker during a demonstration in central London.

Prosecutors said Wildego shouted expletives at police officers and rushed at them after most of the violence had stopped.

Joseph Lord, defending, said Wildego is “wholly ashamed” of her actions and got herself arrested to be with her husband, who had been detained by police earlier.

She was given a suspended sentence because she is a full-time carer for her son, who has learning difficulties.

Dean Groenewald, 32, has been sentenced to two years and two months at Newcastle Crown Court, for his part in rioting in Sunderland – described by the judge as “an orgy of violence” – on the day after three girls were stabbed to death in Southport.

Groenewald has 30 previous convictions including for affray, criminal damage and common assault and was on licence for a previous offence at the time of the Sunderland disorder.

David Engleby, Paul Dryhurst and Luke Summerfield have all been jailed for throwing missiles at police near to a Southport mosque.

Engelby, 29, from Southport, was jailed for two years and four months, Dryhurst, 33, from Litherland, received two years, and Summerfield, 33, from Aston under Lyne in Greater Manchester, was jailed for two years and two months.

The court heard Dryhurst’s parents both work for the ambulance service and are “baffled” at their son’s behaviour.

Judge Watson said: “It would be wrong and misleading to look at the actions of individuals in isolation because violence feeds on itself. Events gain a momentum of their own.”

On Monday Downing Street confirmed it has activated emergency measures to ease prison overcrowding in parts of northern England and the Midlands.

As of last Friday morning there were 87,893 people in jails in England and Wales.

This means institutions were left with an operating margin of 1,298 beds, about 1.5% of the system’s total capacity.

The emergency measures, known as Operation Early Dawn will mean defendants will only be summoned to a magistrates’ court when a space in prison is ready for them.

Court cases could be delayed, with people kept in police holding cells or released on bail while they await trial

Meanwhile the Prisons Service, courts and police will assess which defendants can be transferred from police cells to courts to ensure there is a space for them if they are remanded in custody.