Drug barons from London are targeting Dover and Deal to set up networks pushing crack cocaine and heroin.

The dealers are targeting vulnerable youngsters at schools, colleges, hostels, drug treatment providers and pharmacies.

The rival gangs have carried out “turf wars” to “steal” clients from each other and carry out attacks, a court has heard.

Now a judge has passed more than 42 years in jail sentences – after a police undercover operation called Operation Victory which was run between December 2014 and May this year.

Judge Simon James told Canterbury Crown Court: “Seaside towns like Dover and Deal seem to be under siege in respect to drugs use...seemingly having a thriving and open drugs market on its doorstep.

“One of the unforeseen disadvantages of improved transport links between East Kent and London, is those involved in peddling drugs for profit seeking to increase their sphere of influence and profit.

“This has led to an upsurge in the availability of hard drugs, the resultant crime and the importing into Kent of gang culture and exploitation and violence.”

The judge added: “Highly addictive drugs like crack cocaine and heroin ruin lives.

“Quite apart from the misery they inevitably bring to addicts, they have a corrosive effect on society.

“Those who seek to profit from this evil trade, seemingly oblivious to the effect they have on others, need to understand that such behaviour will not be tolerated.”

He said that gangs from London had travelled to Dover and Deal and set up networks where orders for Class A drugs were done by telephone.

Local drug addicts were then recruited to sell the drugs and the dealings were organised as businesses – sometimes openly advertising the price and quality of the drugs.

The cases were heard during three days set aside to deal with those caught in the undercover police crackdown – led by one undercover officer known as “Dell”.

Prosecutor Donna East said that while Dover is a one of Kent’s smallest urban conurbation in Kent but the problems of drugs supply there “is disproportionate to the rest of the county”.

“Major drugs networks dealing across Dover include offenders from outside the district who choose to supply drugs outside their home area.

“One of the main objectives in Operation Victory was to disrupt and dismantle Class A drug dealing networks operating across the district, which is serious organised crime.”

She added that one of aims by police was to tackle the public perception in Dover that drug dealing “is an ever-present problem”.

The prosecutor said the gangs had a structured tier system with the bosses at the top, who were leaders in the criminal fraternity and exercised the most influence.

The middle group were supervisors and below them “the rest of the crews” – the young and vulnerable and easily manipulated.

Ms East added: “Many of them believe that getting involved will bring them wealth and a street name which will generate a future.

“The reality is usually completely different with threats and intimidation. They target addicts in a proactive and provocative way.

“The undercover officer, known as Dell, infiltrated four networks, the biggest, called Bill, along with Sam, Jimmy and Dingo networks.”

The judge commended officers involved in Operation Victory – “some at considerable person risk” – for their efforts.

Among those who admitted drug dealing were:

Joseph Silkstone, 33, from Canute Road, Deal (12 months suspended for 18 months); Anthony Standen, 36, of Snargate Street, Dover (three years); Deborah Beer 29, of The Street, Staple, Canterbury(two years and her car forfeited); Andrew Lindsay, 18, of Randolph Road, Dover (two years); David Mountjoy, 48, of Eastcliff, Dover(18 months); Cary Barrass, 39, of Tower Hamlets, Dover (two years); Gary Booth , 41, of no fixed address(14 months).

Samuel Little, 19, from Cowdray Square, Deal (four years); Archie Biggington, 19, from Manor Road, Deal (three years); James Pope, 31, from Victoria Park, Dover (two years); Russell Bibby, 37, of Station Road, Adisham (two and a half years); Sam Oluwasegun, 18, of Doria Drive, Gravesend (adjourned until September 9); a 17 year old from Dover (two years detention and training order)

Jason Aldridge, 42, of Templars Street, Dover (three years); Paul Roberts, 41, of Herbert Street, Dover (three years); Billy-Ray Beckham, 18, of Folkestone Road, Dover (four and a half years);Paul Renton, 39, also of Folkestone Road (two years) and Jack Moore, 25, from Liverpool (four years).