In recent weeks ITV News has gone undercover in the makeshift camps holding hundreds of people near Calais. There our team found traffickers offering passage to Britain in return for thousands of euros.
As Brexit approaches, many of those seeking passage to the UK fear it will be tougher to get to Britain, making them even more desperate to make the perilous passage.
Video report by ITV News Correspondent Dan Rivers and News Editor Jonathan Wald
There are between 1,000 and 1,500 refugees and migrants camped out in northern France, around 600 of whom are in Calais.
Some are refugees fleeing persecution from countries such as Iran, Afghanistan and Eritrea.
Others are economic migrants.
They are all desperately trying to cross into the United Kingdom seeking a better life.
An undercover reporter for ITV News spent weeks in the camps of the Calais wastelands known as the "Jungle", eating with them, socialising with them and hearing their stories to capture an intimate portrayal of the desperate measures they take to reach the UK.
Winning the migrants' trust took time.
Initially they were suspicious of the undercover reporter's claim he wanted to bring his nephew over by boat to join him in England.
"The reason some are suspicious about you," one Iranian man told him, "is that you've come from England and a lot of people have come from England who are journalists or intelligence agents."
Our reporter attempted to find a trafficker who dealt in boats, but could only find those who offered transportation by truck - the most commonly used method of crossing into the UK.
"I don't talk too much, I just get on with the job," one trafficker said.
"In one week I will send you, if you don't make it I will give you your money back.
"Come with me, I'll try with you every night and will get you through."
"It's not for me, it's for my nephew," our reporter told him.
"Listen, give me €3,000 and I'll do it for you."
Other migrants recounted a surer but more expensive way of travelling on a truck.
One Afghan migrant told our reporter that "three nights ago someone went on a lorry and he paid €12,000."
"How many were there?" Our reporter asked.
"One person," they replied.
"One person?! Twelve grand, that was a lot? Did they make false documents for him?"
"No, they have a special place hidden that's built in the lorry," the migrant replied.
"Not even a fly or a dog can find it, there's no way to find that place."
As our reporter continued his search for someone organising the launch of a boat bound for Britain, he encountered several people anxious about Brexit limiting their chances of crossing the Channel.
One Iranian migrant told him: "Brexit happens, after that, to get a successful asylum claim is very, very difficult.
"When is it going to happen?"
"In a couple of months time," our reporter replied.
"God willing, I will go before that," the Iranian said.
The boat trips are largely organised and undertaken by Iranians.
It's an avenue of opportunity for crossing of which other nationalities are envious.
"We don't have unity, the Iranians do," one Afghan migrant told our reporter.
After several days it became apparent those planning to go by boat were Hell-bent on arranging the crossing themselves, without traffickers and with good reason in some cases.
"You know my friend?" an Iranian migrant said bitterly.
"He's got a friend called Rachmanov.
"He's a son of a b**** trafficker who ate our money – €1,800 from my friend, €1,100 from me and from the other boy as well.
"We gave him that money to buy us a boat.
"Everyone knew about that story, even the Afghan boys know, ask them, they'll tell you what actually happened.
"So that's the reason we don't actually have money to buy a boat.
"I swear to God, I don't have money."
The same man became wistful about his reasons for leaving home.
"In Iran we have a lot of problems at home," he said.
"My dad had cancer, he lost his other two sons - one died in hospital – we didn't have money to pay his hospital bills and the other died in an accident.
"My mum is 80-years-old, we have a lot of problems back home.
"We kept our mum alive with the help of morphine.
"I came here to work and send money back home."
There are more failures to launch boats than successes.
One migrant recounted how a group of people were "one kilometre away from Dover when they were captured.
"One hour they waited in the water until the French boat came and took them back.
"They tried to argue that they had already made it but they roughed them up, handcuffed them, put them in a room in the boat and they brought them back over to France."
Another migrant told how others "showed them [French authorities] the GPS, they showed them their phones and said 'look this is the proof, we made it into the UK,' but they still didn't believe them, they told them that they were in French waters, not British waters.
"It looks like they were co-operating with each other."
We have no way of confirming this account and whether the boat was as close as one kilometer from the UK coast.
The migrants are rigorous in covering their tracks should they not complete the crossing.
"Can't police trace how and where you got the boat?" Our reporter asks.
"You just have to clear the serial number and then no one is going to find out about you," an Iranian migrant replies.
"Even on the engine there's a serial number and that also has to be cleaned off."
"It only has 2 screws on the side," another Iranian chimes in.
"It's very easy to remove them and drop the engine in the water if they find you.
"Before the police approach it's very easy to remove the screws and drop it in the water.
"There is also a place you can buy the boat without documents."
One Iranian migrant took our reporter to a beach 20 miles west of Calais which they were considering for a launch.
"The first time we did a launch with our boat, the wind was so strong that it lifted the boat out of the water," he said.
"So we said we just have to wait, it's too bad at the moment."
"The only light you will see in the night is Dover," he said looking out towards Britain.
"If you stand on the top of that launch point you will see beautifully-lit Dover."
Moments later two French policemen approached them asking for their documents.
They put them both in detention in Coquelles where the Iranian migrant remained for 12 days.
Upon his release from the detention facility the migrant wasted little time.
As soon as the weather conditions became favourable he and eight friends (seven Iranians and one Afghan) gathered €4,500 to buy a dinghy and an outboard motor from a boat yard 50 miles inland from the French coast.
They recruited a driver to take them and the boat to the launch point intending to launch between midnight and 2am on Tuesday morning.
Their plan started to come unstuck when the driver arrived more than four hours late at 4:15am.
They hurriedly built and pumped up the boat, operating in pitch darkness except for fleeting moments when they risked the use of a torch.
Their first attempt to launch failed when a wave engulfed the boat and flooded the engine incapacitating it.
One of the migrants wept on the beach as he saw his dream of reaching the UK slip away.
The setback may have been a blessing in disguise for the migrants as a French warship was lingering at this time in the direction they would head in.
They had to wait hours for the engine to drain by which time the war ship moved north out of their path.
Somehow they managed to start the engine and at 9.30am successfully launched.
A few hours later, after refusing attempts by the UK border force to transfer them from the dinghy onto the search and rescue boat, they were on British soil in Dover.
The Afghan migrant was arrested on suspicion of facilitating illegal entry but then released into detention after 24 hours with the investigation into the allegation continuing.
None of the conversations our reporter had with the Afghan migrant over several weeks suggested he has ever had a role in facilitating illegal entry.
All nine migrants said they intended to claim asylum upon reaching the UK.
It's unclear what their fate will be.
Some of them at least have given full finger prints in the countries they passed through on their way to the UK, including Germany, Italy and France meaning it's possible that they may be deported back to those countries.