French police could start intercepting Channel migrant boats at the end of May, insiders believe.
Keir Starmer has claimed joint efforts with the French to stop small boat crossings have never been “more effective”.
And the Home Office is pressing Paris to intercept migrants in the water to drastically cut the number of crossings.
Home Office sources hope this could start at the end of May, when a new specialist policing unit trained in tackling public disorder to target smuggling gangs on their coastline begin their patrols.
Sir Keir said: “The final part of the journey, for some, is the north coast of France.
“Obviously we need to work with the French law enforcement there.
“And I think it is right to say that that joint working is more effective and more joined up now than it’s probably ever been.”
French interior minister Bruno Retailleau vowed to “rethink our approach” after talks with Home Secretary Yvette Cooper.
Ms Cooper added: “With France, I think it is really important and the French cabinet has now agreed to the change in the rules, which means that they can now intervene in French waters.
“That was against their rules up until now.
“And previous Governments tried many times to get France to do this and were not successful.
“I think it’s really important that they have made this change that allows them to be able to intervene, especially when we’ve seen these dangerous taxi boats arrive in shallow waters, people then try to crowd them, we’ve seen violence on the beaches.
“It’s hugely dangerous.
“And so this means that they will now be able to take more action in French waters, and we’re continuing to work with them on taking it forward.”
Ms Cooper added: “We’re seeing from month to month, the changes in crossings.
“It is a disgrace that for too long it has been far too dependent on the number of calm days and that’s because the criminal gangs have been allowed to taker such deep root over a six year period.”
At least 60 migrants have been taken back to France by British vessels after being rescued in the Channel, the Daily Express can reveal.
In a sign of improving relations with Paris on migration, three Border Force vessels have been allowed to take asylum seekers back to French ports.
The first British operation took place in October as the two Governments scrambled to prevent more migrant deaths in the Channel.
But the Daily Express can reveal another two British vessels have been given permission to take people back to Calais.
Border Force captains can request permission to dock at a French port if they have rescued migrants from the water.
It is an agreement designed to save lives at sea and the destination is dependent upon factors such as whether there are any medical emergencies or the conditions in the Channel.
Former Prime Minister Rishi Sunak raised the plan – codenamed Operation Windspire – with French President Emmanuel Macron during a bilateral call last Summer.
Under the proposal, British vessels could enter French waters and rescue migrants if they were in distress. The Home Office also considered renting a rescue ship from Poland to conduct more joint operations.
The confidential plan was put into action for the first time in October.
An insider told the Daily Express: “It was always planned that this would be done with French co-operation and would not be possible without their buy-in.”
French police refuse to intervene once a vessel is in the water.
Smugglers have adapted by using so-called “taxi-boats”, where they quietly launch the dinghy in a canal or quieter part of the beach and then pick up larger numbers of migrants down the coastline.
Home Secretary Yvette Cooper has confirmed migrants face up to five years in prison if they refuse to be rescued in the Channel by the French authorities.
The Home Secretary said a new offence will be created to target those endangering another life during a small boat crossing.
Asylum seekers fighting with French police on the beaches, dangling children over the edge of a small boat or “rushing” vessels as they try to launch could all be prosecuted, with a maximum penalty of five years behind bars.
Criminals caught selling or handling small boat parts, such as engines or lifejackets, could also be jailed for up to 14 years as the Home Office will make it “illegal to supply or handle items suspected of being for use by organised crime groups”.
Officials believe they could even extradite criminals operating in countries such as Turkey and prosecute them under this new law.
Ms Cooper has insisted giving Border Force counter-terrorism-style powers will allow the UK to “identify, disrupt and smash people smuggling gangs” faster.
Immigration officers and police will also be able to seize phones, laptops and other electronic devices before they arrest anyone if they are suspected of “containing information about organised immigration crime”.
Home Office sources warn Border Force officers often face “floating crime scenes”, with traumatised migrants unable to speak about the horrors of the fatal crossings.