David Cameron has claimed the deaths of five migrants as they tried to cross the English Channel strengthens the case for the government's controversial Rwanda deportation plan.
Foreign secretary Lord Cameron said the deportation flights were the only way of "busting the model of the people smugglers".
The migrants died in an attempt to launch from French waters near Wimereux at about 2am on Sunday, triggering a major emergency response. According to French media, 72 people, including 10 children, were rescued and taken to Calais while one person was rushed to hospital.
It happened as the government's Rwanda legislation is back in focus, with Rishi Sunak facing a House of Commons showdown this coming week.
Speaking on the BBC's Sunday With Laura Kuenssberg programme, Lord Cameron said: "It's heartbreaking when these things happen, and the loss of life that takes place. You can only think about what an appalling end it would be, in the cold waters of the Channel in the middle of the night. It breaks my heart to hear about it. But it just shows we've got to stop the boats, we've got to stop this illegal trade in human beings."
Lord Cameron added: "We have done a huge amount. We have given a vast amount of money to help the French with the policing and intelligence operations. We have done a vast amount in the Channel itself, but ultimately the only way you can stop the boats is by busting the model of the people smugglers by making sure that if someone goes from point A in France to point B in Britain, they do not stay in Britain – that that route doesn't work.
"In an ideal world you'd just send them straight back to France and that would be it, and the whole trade would collapse. That is not available and that is why we are pursuing the policy with Rwanda. That's why the bill will be passed next week, that's why the treaty has been signed.
"Yes, it may be unorthodox or unusual, but unless we can get flights off [to Rwanda] and get that system working so people know there is no point getting on that boat in France... once we've done that we will be able to collapse this trade even more."
Labour leader Sir Keir Starmer, appearing on the same programme, described the deaths as a "tragic loss of life" but said he did not support radical action like the Rwanda plan.
"I think he [Lord Cameron] is wrong about that," he said. "I absolutely agree that we need to stop these Channel crossings. They are dangerous, we have lost control of our borders, and we need to do something to stop the boats. I think the starting place for that is to go after the criminal gangs that are running this vile trade."
What is happening with the Rwanda plan?
The number of small boat arrivals in Britain last year was 29,437, the second highest annual total on record.
As part of Sunak’s pledge to "stop small boats" crossing the English Channel, he wants to deport migrants who do so on a one-way trip to Rwanda, where they will be able to seek asylum in the African nation.
The Supreme Court ruled against the plan in November, saying people sent to Rwanda would be at risk of human rights breaches. Sunak responded by introducing a new bill to Parliament to make the scheme legally watertight.
Next week is key for the proposed legislation. The Safety of Rwanda (Asylum and Immigration) Bill's committee stage – the third of 11 hoops a bill needs to go through to become law – will be held on Tuesday and Wednesday.
However, Sunak is facing the threat of rebellion from both sides of the parliamentary Tory party. Dozens of right-wing Conservatives are backing amendments to the bill aimed at effectively ignoring international law and to severely limiting individual migrants' ability to resist being put on a flight to Rwanda.
But accepting measures from the right of the party would risk angering the centrist One Nation wing, which wants to ensure international law is respected.