Home Secretary stresses UK border security

She said it was "crucial" to have vigilant officers using the best technology at ports and other entry points.

She travelled to Heathrow Airport Terminal 5 to see for herself the kind of border control checks and searches in place.

The Government has pledged to create a new border force to enhance national security and improve immigration controls.

The force will be part of a shake-up of the Serious Organised Crime Agency, which will incorporate the UK Border Agency.

Speaking at Heathrow, Mrs May said: "This was a valuable opportunity to meet front line officers and see first hand the challenging work they carry out every day.

"Keeping Britain's border secure is a priority for this Government – which is why it is crucial that we have vigilant border staff utilising the latest technology in our

fight against the people traffickers, drug smugglers

and illegal immigrants determined to come here and cause harm.

She said the Government was committed to curbs that would bring net migration back to the levels of the early 1990s – "tens of thousands, not hundreds of thousands".

"If this is to happen successfully, our border must be stronger than ever before."

Airport officials use body-scanning equipment, sniffer dogs and devices that can detect nuclear and other radiological materials to try and flush out illegal materials.

Immigration staff employ forgery detection techniques such as using powerful magnifying equipment and light machines to spot fraudulent paperwork.