BORDER controls were secretly relaxed at all ports including in the North-East and Yorkshire, the Home Secretary admitted yesterday as the passport scandal deepened.

Theresa May said the policy of not fully checking all biometric passports – thought to have been introduced at Heathrow and Calais to cut holiday queues – was sanctioned nationwide.

In the Commons, Ms May admitted the number of suspected terrorists, criminals and illegal immigrants who slipped into the country “will never be known”.

Labour stopped short of calling for the Home Secretary’s resignation, but accused her of “presiding over growing chaos and cornercutting at our borders”.

The Opposition also published the “operational instructions” sent to border agency staff in July, claiming it contradicted her insistence that checks were relaxed for visitors from outside the EU, without ministerial approval.

Ms May was forced to make a statement after Brodie Clark, the director of border control for the UK Border and Immigration Agency (UKBA), was among three officials suspended last Thursday.

Mr Clark allegedly authorised the dropping of biometric checks, the verification of fingerprints and checks against official watchlists of terrorists and criminals on non-EU nationals at busy ports.

Yesterday, Ms May told MPs she had agreed, in July, to a trial to limit certain checks to allow border staff to “target intelligence-led checks on higher-risk categories of travellers”.

As a result, visitors would not always have the biometric chip opened on their passport – but only if they arrived from within EU countries.

Ms May said she had only discovered last week that officials had gone further, by relaxing checks on people from across the world. John Vine, the UKBA’s independent chief inspector, is investigating.

But she was heckled when she first insisted Manchester Airport was not part of the trial, only to add, seconds later: “It was possible for the pilot to be operated across all ports.”

Worse, Labour produced the leaked document, suggesting ministers had delegated authority for relaxing checks on all arrivals to border force officials.