The Public Accounts Committee (PAC) said the body tasked with securing Britain's air, sea and rail ports admitted it was failing to meet eight of its 19 performance targets.
It meant freight went unchecked for illicit goods and illegal immigrants were able to sneak in while Border Force officers focused on carrying out checks on every single passenger coming into Britain.
Committee chairwoman Margaret Hodge said: "The Border Force prioritised passenger checks on arrival at the expense of other duties and weakened the security of our borders.
"The force neglected to examine freight for illicit goods, neglected to check lorries in Calais for concealed illegal entrants, and failed to check passengers coming into Britain on private planes or boats, potentially letting billionaire gangsters off the hook.
"The morale of staff is at rock bottom, threatening the prospect of achieving the increases in productivity and flexibility of workforce which the Border Force so sorely needs."
The PAC said Border Force needs to set out plans for how it will meet all of its obligations from now on.
And it needs to acknowledge how this will be done better in a time of squeezed budgets.
The committee highlighted that in recent years the number of officers has been cut, only to go straight back up again.
A clear timescale should also be laid out for improvements to the IT systems assisting the work of officers, the MPs concluded.