Doug Bannister, chief executive of the port, said "woefully inadequate" staffing in France was to blame for the disruption.
"Knowing we are now in a new world of post-Brexit and Covid checks, we worked to increase interim French border control booths by 50% and have improved traffic systems in order to build in resilience and capacity in time for the summer," he added.
"We have worked particularly hard, and extremely positively up to now, with our Police Aux Frontieres (PAF) colleagues over recent months to plan for the traffic volumes that were fully expected."
