”Budget cuts and shortages of guards are blamed for handing thousands the chance to slip in along the East coast.
The majority caught were single men from Albania, Afghanistan and Iran in search of cash-in-hand work.
Alp Mehmet, from Migration Watch UK, said: “If these gaps are not plugged, people smugglers will exploit them to the full to feed the insatiable appetite of the black economy.
Many detained do not bother to claim asylum and prefer to make further attempts to enter the UK undetected, according to the report by the Independent Chief Inspector of Borders and Immigration.
Although Calais remains the departure point of choice for many, traffickers and crime gangs are now turning their attention to ports like the Hook of Holland, Rotterdam, Zeebrugge and even up to Scandinavia.
Detections of illegal migrants at east coast ports jumped 82 per cent between 2014/15 and 2015/16 from 233 to 423, the chief inspector found.
The number claiming to be minors had increased while thousands more are thought to have got through successfully.
The report said: “A significant proportion [of illegals] did not claim asylum in the UK but agreed to prompt removal. Border Force officers assumed this was because these individuals would make further attempts to enter the UK clandestinely, drawn by the ‘pull factor’ of access to paid work in the ‘shadow economy’.
“Officers believed rumours to the effect the fee charged by criminal gangs covered three facilitated attempts to enter clandestinely.”
Of 95 files sampled, 37 clandestine arrivals left from Zeebrugge, 20 from the Hook of Holland, 17 from the Port of Rotterdam, and nine from Europort [Rotterdam].
Of the remaining 12, two had embarked at Esbjerg in Denmark and one each at Gothenburg in Sweden and Cuxhaven in Germany.
Ukip defence spokesman Bill Etheridge said: “The findings are damning and show huge gaps in the UK’s border security.
Bill Etheridge – The Calais Jungle
Published on Aug 25, 2016
BILL ETHERIDGE – A CANDIDATE NOT AFRAID TO GET HIS HANDS DIRTY AND FIND OUT THE FACTS FOR HIMSELF.
“It’s clear there needs to be a shift in resources away from unnecessary projects and towards Border Force.”
Inconsistent working practices were blamed for allowing the migrant threat to explode. Border Force at Hull was seen to carry out searches of arriving vehicles but none were seen at Harwich.
Both ports receive passenger vehicles from Hook of Holland. Incredibly, officers told inspectors that Harwich in Essex relies on checks carried out by Dutch authorities.”