Agency workers were recruited to fill gaps in Britain's Border Force in the run-up to the end of the Brexit transition, MPs were told today.
Bosses needed to hit a target of 1,570 extra staff by December 31 and turned to a high street agency to find workers.
The temps are now carrying out “transit checks” on freight carried across the Channel.
UK Border Force director-general Paul Lincoln told the Commons Public Accounts Committee: “We had 1,570 people in.

“Some of those were contingency staff which we took from agencies, which was a deliberate decision which we took earlier in the year to allow us to continue training more permanent staff.
“But we had exactly the number of resources, plus some contingency on top of that, in place for December 31 – 100% trained to do the roles which they were expected to do.”
The Brook Street agency was used to recruit staff “who are conducting some of our transit checks at the inland border facility sites”, Mr Lincoln said.
He added: “It's a relatively short amount of training, it's conducted by our experienced trainers within Border Force and all of the people we have put through that training are, to our satisfaction, able to do the job we have assigned to them.”
Some hauliers have complained about added checks and delays crossing the Channel since the Brexit transition ended at 11pm on December 31.
But the huge queues many feared have, so far, failed to materialise.

However, experts warn trade is still to hit normal levels after the Christmas break because of previous stockpiling, and ongoing travel restrictions caused by the coronavirus pandemic.
Lorry drivers entering Kent to use Channel ports or the Eurotunnel terminal at Folkestone need a 24-hour Kent Access Permit.
By Monday, 636 fines had been issued to hauliers without permits.
But the Department for Transport's top civil servant, permanent secretary Bernadette Kelly, told MPs there was “strong compliance” with the regime.