This article is more than 11 months old

This article is more than 11 months old

The government is to spend £20m on tackling county lines drug networks, including recruiting more specialist caseworkers to deal with victims groomed into gangs, the home secretary has announced.

County lines involves gangs in cities such as London, Birmingham and Liverpool using children as young as 11 to deal mostly heroin and crack cocaine over a network of dedicated mobile phones.

In her speech to the Conservative party conference in Manchester on Tuesday, Priti Patel said the extra cash would stop gangs “terrorising our towns and villages and exploiting our children”.

The package will be spent on expanding the National County Lines Coordination Centre and setting up a dedicated unit within the British Transport Police, which will deploy visible and undercover officers at railway stations to disrupt county lines activity.

In the Behind the Lines series, the Guardian revealed the soaring number of cases in which vulnerable children are linked to gangs as well as cases of British victims of human trafficking who have been forced to sell drugs in county lines operations being charged and prosecuted despite guidelines against doing so.

The number of individual phone numbers identified by law enforcement officials as being used on established county lines networks is about 2,000 and the illicit industry is estimated to be worth at least £500m.

Patel’s speech focused heavily on policing and only briefly touched on other policy areas within her brief such as immigration. The address was full of tough-on-crime rhetoric that has become a staple of Boris Johnson’s domestic agenda.

Addressing unspecified criminals, Patel said: “We are coming after you … We stand for the forces of right, and against the forces of evil.”

The home secretary announced a £10m “safer streets fund” for police and crime commissioners to invest in preventive measures, such as CCTV and street lighting, to tackle burglaries, thefts and shoplifting in crime hotspots.

Since becoming prime minister, Johnson and his cabinet have made a wave of justice-focused announcements, including increased use of stop and search, more police officers on the streets and a review of sentencing.

Earlier in the session at the party conference, the justice secretary, Robert Buckland, in a pre-recorded video announced proposals to end automatic release at the halfway point of a prison sentence for more violent and sex offenders in England and Wales.

Buckland said offenders guilty of violent and sexual crimes that carry a maximum sentence of life – such as manslaughter, rape, grievous bodily harm – and who were sentenced to at least four years in prison would be required to serve two-thirds of the sentence in prison before being released on licence.

He also announced plans to roll out so-called sobriety tags nationally for use on offenders convicted of alcohol-related offences.

The bracelets monitor blood alcohol levels and transmit them to a base station every 30 minutes. Those who fail to comply with the conditions are returned before the courts.