France has put in motion a contingency plan to deal with an eventual "hard Brexit", including 50 million euros ($57m) of investments to help ports and airports cope.

Prime Minister Edouard Philippe told reporters on Thursday that there were "strong fears" Britain would leave without a deal on March 29.

"What's certain is that the scenario of a no-deal Brexit is less and less unlikely," said Philippe.

"In such a situation, the government's responsibility is to make sure the country is ready, that the interests of our citizens are looked after. That's why I've decided to trigger the plan for a no-deal Brexit."

Five decrees will be issued in the next three weeks, looking at different aspects of the relationship between the two countries. 

The first decree is expected to cover the rights of British citizens in France, and it allows the continued operation of UK companies in regulated sectors. It also allows British citizens to continue living in the country for 12 months, during which they can apply for authorisation to remain in the country. 

The second looks at the increased control measures at ports and airports, and will "lighten certain formalities".

The third allows road transport operations in France.

France will also look to ensure the smooth running of financial services that could be jeopardised by Britain losing its "financial passport". The final decree guarantees military equipment exchanges between the two countries. 

"Brexit will be a change but we are determined to maintain the excellent level of cooperation between the two countries," said Philippe.

European concern

Businesses are concerned about potential disruptions in the case of a hard Brexit. But France is not the only country that is on alert.

Dutch Foreign Trade Minister Ingrid Kaag said that the Netherlands will launch a major information campaign on January 28.

Germany said it will do all it can in the coming days to ensure that a deal is in place for when Britain leaves the European Union.

However, Foreign Minister Heiko Maas stressed that, given the continued parliamentary deadlock in Britain over the terms of Brexit less than three months before the planned withdrawal, Germany would step up preparations for a disorderly Brexit.

Prime Minister Theresa May's two-year attempt to forge an amicable divorce was crushed by the British parliament on Tuesday in the biggest defeat for a British leader in modern history.