The government's failure to secure Britain's borders is leaving the country open to potential terrorist attacks, Michael Howard has warned.

Detailing his party's immigration plans at a press conference on Tuesday, the Conservative leader pledged to delegate responsibility for border control to a new single police force.

"We face a real terrorist threat in Britain today - a threat to our safety, to our way of life, and to our liberties," said Howard.

"But we have absolutely no idea who is coming into or leaving our country.

"There are a quarter of a million failed asylum seekers living in our country today.

"No one knows who they are or where they are.

"To defeat the terrorist threat we need action not talk - action to secure our borders."

'One face'

Howard pledged to establish a new British Border Control Police so that there is "one face at the border".

"One police force, with one chief constable, with just one job: securing Britain's borders," he said.

The Tory chief said the move would lead to more effective action to protect the UK.

"The clearest line of accountability in any organisation is to a single individual: a person who sits behind a desk with a sign that says 'I'm responsible - the buck stops here'," he added.

"Britain is an island nation. We can control our borders. 

"But it will only happen if we have a government with the determination to act."