The Home Office has been told by MPs to get a grip on a scheme to secure the UK's borders, which is set to be at least eight years late and cost £1bn.
The e-borders scheme, launched in 2003, has been dogged by problems and in 2014 was "terminated" in its current form.
The Public Accounts Committee accused officials of complacency and said delays in implementing its successor risked undermining Britain's security.
The Home Office said it was considering the report's findings.
The e-borders scheme is designed to enhance checks on people entering the country by air, rail and sea by gathering and processing data on passengers before they reach the border.
The cross-party committee said the new system was not expected to be in place until "at least" eight years later than planned and cost "significantly more than expected".
It found that repeated warnings about the original e-borders scheme and its successor had not been taken seriously, saying officials had been "worryingly dismissive".
"It is difficult to understand where this confidence comes from, given the lengthy delays and continual warnings of ongoing management issues, which gives us cause for concern about the future prospects for this programme which is vital to national security," its report said.
What are e-borders?
- Launched in 2003, the scheme was originally meant to collect details from passenger lists of all people entering and leaving the UK
- The US firm handed the £750m contract, Raytheon, was fired by the coalition in 2010
- The e-borders contract was split in two with IBM and Serco given the job of getting a system in place at nine airports before the 2012 London Olympics
- In 2014, the director general of the UK Border Force said "full e-borders capability", as originally envisaged, would not be achieved, but the checks and screening would be incorporated into a new programme.
Seven warnings about the programme had been issued by the Major Projects Authority since 2010 and in 2015 the National Audit Office said checks remained "highly manual and inefficient" and the IT systems were outdated.
The report found that only 86% of those coming to Britain have their data checked ahead of travel, despite a pledge to carry this out on 95% of travellers by December 2010.
Committee chairwoman Meg Hillier said: "If the Home Office is to complete this project before the decade is out, then it must get its house in order now - starting by setting out exactly what it expects to achieve this year, and who will be held to account for it."
The Home Office said it would respond to the report "in due course".
A spokesman for the department said defending the UK's borders was its "top priority" and "we are investing heavily in our systems to tackle the threat from terrorism, organised crime and illegal immigration".
"Every passenger crossing our control points into the UK is checked against a range of watch-lists and the UK passport is among the most secure in the world.
"When the e-borders contract ended in 2010 we took immediate steps to stabilise and modernise crucial but old-fashioned systems.
"This included a £23m investment in new Warnings Index technology, which is now operating at a higher level than ever before."