President Macron and heads of other member states fear Britain could gain advantage over them by undercutting EU environment law.
After talks with fishing industries, British fishing boats will receive compensation in return for staying out of the Baie de Seine off Normandy.
New force would not be within the European Union and would allow non-EU, such as Britain, to be part of it, said French defence source.
French President Emmanuel Macron Thursday said the poisoning in Britain of exiled Russian former double agent Sergei Skripal and his daughter Yulia apeared 'attributable' to the Russian authorities, describing it as an 'unacceptable attack on the soil of an allied country' and pledged to announce retaliation measures 'in the coming days'.
British Prime Minister Theresa May has said French President Emmanuel Macron agreed that their two governments 'should coordinate closely' over the growing crisis between London and Moscow following the poisoning of a former Russian double-agent and his daughter in an English town earlier this month.
New arrivals in France lack rights and help in navigating minefield of bureaucracy, French MPs have been told.
Britain, which usually imports power from France, has been exporting it across the Channel in November, as operators of the eight remaining British coal power stations appear to be taking advantage of higher purchase prices and outages of French nuclear reactors.
An 36-year-old officer with the British border control agency Border Force was arrested in northern France along with three other Britons when handguns, ammunition, cocaine and heroin were found in their posession, in a joint operation into a suspected weapons and drugs smuggling ring by police in France and Britain.
Anti-human trafficking ONGs have raised the alarm over a camp in northern France known as Vietnam City where, hidden in woodland on the site of an old coalmine, they say up to 100 Vietnamese migrants, some of them minors, are housed in poor conditions awaiting passage to the UK to work illegally in cannabis farms, nail bars and restaurants.
Interior minister Gérard Collomb said returning border to England would be 'complex' but Paris wants more 'favourable conditions' over costs.
At a press conference following the meeting in Paris on Tuesday evening between French President Emmanuel Macron and UK Prime Minister Theresa May, the French head of state, who has previously warned May that a tough deal awaits Britain's referendum decision to leave the EU, said of the so-called Brexit negotiations that until they come to an end 'there is always a chance to reopen the door'.
With elections afoot in both their countries, French President Emmanuel Macron and British Prime Minister Theresa May each claim to lead the world's fifth-largest economic power, and the plain facts demonstrate that the two economies have very similar performance in a number of areas.
President François Hollande, speaking at a UNICEF conference in Paris on children caught in conflict, slammed the British government's refusal to take in more migrant minors with family already settled in Britain and who are now stranded in France.
Former economy minister and independent centrist candidate in France's presidential elections, Emmanuel Macron, who increasingly appears to be within reach of the final round of the polling in May, said Britain was 'becoming the junior partner of the United States' after previously living 'in an equilibrium with Europe'.