BORDER checks were relaxed hundreds of times at UK ports, including in the North-East and Yorkshire, under a pilot scheme authorised by Home Secretary Theresa May this summer, figures show.

Fresh evidence released by Labour also showed that passengers on private jets were let into the UK without even being seen by border officials.

The latest disclosures will put further pressure on the under-fire Home Secretary as the former head of the UK Border Force, who quit his post over the border checks row, prepares to be questioned by MPs tomorrow.

Brodie Clark, 60, who resigned last week after a 40-year career in the Home Office, is expected to say he only acted to relax border checks because he was required to do so by the police to prevent overcrowding.

Leaked emails between UK Border Agency (UKBA) officials showed the controls were eased a total of 260 times in one week alone this summer.

Other leaked documents showed passengers on private jets were able to enter the UK without being seen by border officials, raising fears among staff that security was being compromised.

Labour published emails from a UKBA official based at Durham Tees Valley Airport who said relaxed checks at the port brought in in March "were creating a situation where we are not able to secure the border as robustly as we would like to, for no justifiable reason.

"We have no way of checking whether the handling agent information is correct or even if the number of people arriving on the plane matches the number we have been advised," the official said.

But managers replied that there was a new national GA (general aviation) strategy being rolled out which was consistent with national policy.

Managers added that they were confident that the risk posed by the private jets could be met by robust risk assessment and risk testing.

One manager also tried to reassure the officials that "there will be no accusation of dereliction of duty as long as the procedures have been followed and the appropriate checks done by the officers."

A UKBA spokeswoman said: "It is not true that we don't carry out passport and warnings index checks on private flight passengers and will deploy officers to airfields where we have concerns."

Meanwhile, in a letter to the Commons Home Affairs Select Committee, Mrs May confirmed the pilot scheme, which suspended the checks on biometric passports of EU travellers and was available to all ports, was used at both Heathrow and Gatwick airports, and at Calais.

It was also used at the ports in Leeds Bradford and Newcastle, as well as Aberdeen, Belfast, Bournemouth, Bristol Airport, Cardiff, Coquelles, East Midlands, Edinburgh, Exeter, Glasgow, Harwich, Liverpool, London City, Luton, Manchester Airport, Newhaven, Norwich, Plymouth, Poole, Portsmouth, Prestwick and Stansted.