Record numbers of migrants gathering in Calais have sparked fears of a summer of violence and chaos.
Latest figures suggest 7000 migrants are at the squalid "Jungle" camp seeking to get to the UK.
On Friday hundreds of Afghan and Sudanese men wielding guns and knives fought bloody battles over smuggling routes. A French police source said: "Hundreds of men were involved in the trouble and many ended up with stab wounds.
"One person was shot and fires broke out. Around 40 men were badly hurt and a police officer was also injured."
Ukip MEP Mike Hookem said: "Now the weather is getting better it is a prime time for migrants. The incentives for getting to Britain are still there. Until we take control of our borders we will continually face this. Voting for Brexit sends the message the UK is not part of the freedom of movement narrative."
Last summer armed and hooded migrants brought motorway traffic to a standstill as they tried to clamber aboard trucks and lorries heading to the Calais ferry terminal.
Despite tens of millions of pounds spent upgrading security in Calais and neighbouring Coquelles last year, experts said the next few months could be worse.
Last summer's chaos cost the transport and logistics industry an estimated 21 million ($46m). James Hookham, of the Freight Transport Association, said: "The Port of Calais handles 89 billion worth of UK trade every year - it's a vital trade route that must be protected."
Meanwhile, Britons are feeling the full effect of the French fuel strike as dozens of petrol stations near the port of Calais had run dry.
Tony Henderson, a Belfast-based lorry driver, said some filling stations had rationed motorists to just a quarter of a tank.