Amnesty International UK made the comments as tensions between London and Paris rise following the deaths of 27 migrants off the coast of Calais.
Human rights group Amnesty International UK said it has "no optimism" about an improvement in the cooperation between Paris and London over the migrant crisis.
It comes as tensions between France and the UK are rising after French President Emmanuel Macron appealed for more European cooperation to prevent illegal immigration following the deaths of 27 migrants off the coast of Calais and record numbers of migrants attempting to cross the English Channel this year.
The International Organization for Migration (IOM) said Wednesday's accident was the biggest loss of life in the English Channel since it had begun collecting data.
Cooperation between the two countries appears to be going downhill after Britain's Prime Minister Boris Johnson share a public letter addressed to Macron on social media asking for France to immediately start taking back migrants who had arrived in the UK from France.
Johson's move triggered a strong reaction from Paris.
Darmanin cancelled planned meetings with his British counterpart Priti Patel on Friday, while the French President said he was "surprised" by the approach taken by the British Prime Minister, adding that leaders should not communicate with each other via social media.
Some had hoped the accident would be a turning point for EU member states and the UK to finally work more closely together on stopping illegal migration.
But Amnesty International UK's Refugee and Migrant Rights Programme Director, Steve Valdez-Symonds, does not share the same optimism.
"I have no optimism about that whatsoever because the key issue is not merely cooperation, the question is cooperation at what?" he told Euronews.
"You can go back to six years ago, the EU produced its own action plan on tackling smugglers. It made absolutely clear that central to those efforts must be safe and legal alternatives for people to take away some of the smugglers' business."
"Countries are not doing that right across Europe, including the UK and France, and I'm afraid what has happened is that smugglers have been left with all of this business, which they've heavily invested in because the returns are so great, and with fewer alternatives that are made smugglers will continue to thrive," he went on.
Valdez-Symonds believes that cooperation between France and the UK should start with London agreeing with Paris that it will accept some of the migrants in its asylum system while asking for France to secure everyone else's arrival in the French system.
"Let's just look at the situation in northern France where you have a relatively small number of people who wish to seek asylum in the UK or to get into a safe asylum system in France. And you have France, which receives a very much larger number of people into its asylum system than does the UK. Cooperation should surely start with the UK agreeing with France that it will accept some of those people, particularly those with close connexions and family here into the UK, to our asylum system while asking that France to make sure that everyone else gets safely into the French system," Valdez-Symonds noted.
Migrants should also be offered safe alternatives to the border crossings.
"If governments are serious about ending these dangerous journeys – I won't say illegal crossings, people are perfectly entitled to cross borders to seek asylum, and that is what these people are doing – but if governments want to stop dangerous journeys and they want to stop smugglers' profits, they need to provide people, who are reliant on those smugglers, with safe alternatives. And without that, I'm afraid we will continue to see tragedies like this," he added.