Clear minimum standards for border checks will be brought in after last year's row exposed staff cutting corners and acting without ministerial approval, the Immigration Minister said today.
Damian Green said the correct level of checks "for every type of passenger and all types of goods" would be set out, with guidance making clear that these could be strengthened in high-risk cases, and setting out the circumstances where they could be suspended.
But he also blamed the failures which saw hundreds of thousands of people let into the UK without proper checks last summer on the previous Labour government.
Coalition Government ministers simply inherited a legacy that "left a lot to be desired", he said.
"We inherited a Border Force that failed to conduct all the checks it should have done - mothballing expensive new technologies and cutting corners to manage queues or other pressures," he said.
"A Border Force where communications between staff and managers were unclear, and where our policy towards key checks was ambiguous or non-existent.
"This was completely unacceptable.
"That's why, when we discovered that there had been an unauthorised suspension of passenger checks at some ports last summer, action had to be taken. And action was taken."
Mr Green said they were "much bigger problems than anyone could have imagined", adding they were "problems kept hidden from ministers in successive governments".
Speaking at a border security conference at the Royal United Services Institute (Rusi) in Whitehall, central London, Mr Green said a "new framework of border security checks" would be brought in, with "clarity about the minimum standard of checks and the circumstances where checks can be suspended".
"The first step in the process to ensuring the Border Force becomes a fully effective law enforcement organisation is to introduce a new operating mandate for the controls it operates at the border," he said.
"The mandate will make sure that we have more control over operations at the border by clearly setting out the correct level of checks for every type of passenger and all types of goods that cross the UK border. In both directions."
Wiltshire Police chief constable Brian Moore was appointed as the new head of the Border Force when it was split from the troubled UK Border Agency (UKBA) at the start of the month after an official investigation found confusion, poor record-keeping and ambiguous instructions were rife.
The move will bring "a genuine law enforcement culture to the Border Force for the first time", Mr Green said.
"We're strengthening our border because for too long it was not strong enough."
Shadow immigration minister Chris Bryant said: "Damian Green has a cheek.
"The truth is that the experiment he and the Home Secretary engaged in last year led to a significant downgrade in the controls at our borders.
"Far from him discovering the weakness in the UKBA, it was Labour's campaign that exposed the scandal of the Government's incompetence.
"Indeed, the instructions from the minister and the Home Secretary were so ambiguous that people in UKBA had no clear idea what was expected of them."
He went on: "Green and May have been in post for two years now.
"It's time they took responsibility for what has happened on their watch."