Nigel Farage, the Ukip leader, has said the government's unwillingness to take stronger action on immigration has worsened the situation in Calais, where disruption caused by striking ferry workers has led to massive delays.
Migrants have been using the delays in the French port to break into trucks bound for the Britain.
Farage told LBC radio that Britain needed to send a "clearer message" to those hoping to travel to the UK illegally.
The British actually could stop, or at least ameliorate, the situation in Calais by sending out clearer messages. Unfortunately, we never seem to do that.
The Ukip leader said that those seeking to enter the UK illegally "know they can come to Britain and work in the black market".
"They [know they] are unlikely to get caught and if they are caught, they're very unlikely to get sent back," he said.
The video, obtained by ITV News, shows scores of migrants desperately trying to board lorries in a restricted area within the tunnel.
Leaders in France and Britain today pledged to work together and increase funds to help stop migrants smuggling their way across the Channel
Arrest, deportation, detention centres and seeking asylum. The next battle for migrants who make it to Britain.