People who put migrants on boats to the UK in rough weather conditions are murderers, the head of Calais port has said.

His comments come after more than 30 asylum seekers drowned while trying to reach the UK this afternoon, in the worst Channel crossings tragedy ever seen.

Motionless people were plucked from the icy water after a dinghy capsized off Calais, with as many as 50 reported to be on board at the time.

A major search and rescue operation remains underway, with three helicopters assisting British and French boats.

Jean-Marc Puissesseau, the head of the port of Calais, has slammed people smugglers who help facilitate perilous crossings.

"I think the people who are paid by the migrants to get to your country, with such bad weather, with such rough sea, they are murderers," he said.

"They don't have any success trying to cross with these weather conditions. The sea is cold and the waves are big.

"They are murderers, and the poor migrants who have spent months and months to come to here, and who die so close to their dream...I don't know what to do really."

His words are echoed by French interior minister Gerald Darmanin, who added: "We cannot say enough about the criminal nature of the smugglers who organize these crossings."

Speaking this evening, Boris Johnson said he is "shocked and appalled and deeply saddened by the loss of life at sea in the Channel".

He said: "This disaster underscores how dangerous it is to cross the Channel in this way, and it also shows how vital it is that we now step up our efforts to break the business model of the gangsters who are sending people to sea in this way."

He added that the disaster shows steps the Government has taken to help tackle dangerous migrant crossings "haven't been enough".

"I say to our partners across the Channel, now is the time for us all to step up, to work together, to do everything we can to break these gangs who are literally getting away with murder," he said.

"What this shows is that the gangs who are sending people to sea in these dangerous craft will literally stop at nothing.

"But I'm afraid what it also shows is that the operation that's being conducted by our friends on the beaches supported with £54 million from the UK - all the technical support we've been giving - they haven't been enough.

"Our offer is to increase our support, but also to work together with our partners on the beaches concerned."

Boris Johnson is set to hold an emergency meeting of COBRA following today's disaster.

Home Secretary Priti Patel said: "It serves as the starkest possible reminder of the dangers of these Channel crossings organised by ruthless criminal gangs."

She says the Government’s New Plan for Immigration "will overhaul our broken asylum system and address many of the long-standing pull factors encouraging migrants to make the perilous journey from France to the United Kingdom", adding that the Government will ramp up efforts to prevent asylum seekers embarking on deadly journeys.

Dover MP Natalie Elphicke too said today's "absolute tragedy" demonstrates why stopping gangs sending boats on the perilous trip is crucial.

She said: "As winter is approaching the seas will get rougher, the water colder, the risk of even more lives tragically being lost greater.

"That's why stopping these dangerous crossings is the humanitarian and right thing to do."

"People smugglers are a symptom, not a cause of the problem..."

But Clare Moseley, founder of migrant charity Care4Calais, says the Government's focus should be upon creating a "safe and legal" way for people to claim asylum, not clamping down on people smugglers.

"People smugglers are a symptom, not a cause of the problem," she told Sky News.

"The underlying issue is the fact that if you want to claim asylum in the UK you have to be physically present here and these people don't have a way to get here. That's why they get in small boats.

"[The Prime Minister] needs to create a safe and legal way for them to claim asylum.

"Nobody's saying 'open the borders, let everyone in'. We're saying let's properly assess their claims, let's see who deserves asylum, and the people who do, we'll give it to them. "

Today's tragedy has been met with anguish by charities that have long campaigned to tackle the "dangerous situation at the border" faced by migrants trying to reach the UK.

Care4Calais says it is "devastated" by the news.

It tweeted: "More than ever why we need a modern system of safe, legal routes enabling refugees to apply for asylum in the UK.

"After today's tragedy, the UK asylum system must surely be regarded as intolerable by all reasonable people.

"On behalf of those who have died, we again urge the Government to scrap its anti-refugee bill and introduce a fair, modern system now.

"For humanity's sake. Please."

Charlotte Kwantes, head of Utopia 56, a charity working with migrants, added: "For years we have been denouncing and warning about the dangerous situation at the border.

"As long as safe passage routes are not set up between England and France, or as long as these people cannot be given paperwork to stay in France, there will continue to be deaths at the border, whether [Gérald] Darmanin comes to Calais or not."

Folkestone and Hythe MP Damian Collins has described today's incident as "an avoidable tragedy".

Echoing sentiments expressed by the Prime Minister and other Parliamentarians this evening, he said: "We must stop these crossings and crack down on the criminal gangs that profit from them. We have to show that the crossings are futile and will not lead to a permanent right to stay in the UK."

Responding to news of the fatalities, French Prime Minister Emmanuel Macron said: "My thoughts are with the many missing and injured, victims of criminal smugglers who exploit their distress and injury."

Labour MP for Canterbury, Rosie Duffield, took to Twitter to express her sorrow for those who have died, adding: "These are human beings, fleeing from an awful situation, desperate enough to risk this dangerous nightmare journey."

Archbishop of Canterbury Justin Welby added: "This was a devastating loss of human life.

"We need a better system based on safety, compassion, justice and cooperation across frontiers. This cannot go on."

The Channel is the busiest fishing lane in the world and despite repeat vows from the UK and French governments to stop people risking their lives to cross numbers have surged and now stand at more than 25,700 in 2021, triple 2020's total.

Asylum seekers have died in the past trying to reach the UK and today's death toll surpasses the tragic death of a family, including two children and a baby, last October.

'Time to stop the blame game': Analysis by political editor Paul Francis

For all the words of collaboration and partnership it has often seemed that the UK and France have been miles apart when it comes to the issue of how to resolve the Channel crossings crisis.

Yes, there has been dialogue and various initiatives.

Not only that but the government has agreed to give £54 million to the French authorities to help tackle the criminal gangs who are masterminding the crossings across one of the busiest shipping routes in the world.

But too often it has seemed that the domestic political agenda of the two governments has intervened in the endeavours to find a way through.

Despite the talk is of bilateral agreements and rendering the Channel "unviable" the stark reality is that the trajectory of the numbers taking the perilous journey is still heading in the wrong direction.

The tragedy unfolding tonight must be the spur to finding a solution. There has to be fresh impetus and direct action. Above all else, the two sides must stop the blame game and show a genuine commitment to finding a way to curb the numbers risking their lives.

We will hear in the coming days warm words from both UK and France, along with plenty of pledges. The acid test will be whether they go beyond just rhetoric.