A further lockdown in France "would probably become an absolute necessity" if the circulation of the English coronavirus variant increases "significantly", Health Minister Olivier Véran warned on Thursday.
He added that the spread of the variant on French territory may be a determining factor in the strategy the government employs to combat the virus in the coming days and weeks.
Citizens in metropolitan France must currently abide by a strict nationwide curfew from 6 pm to 6 am every day, and must only leave their residence between these times for a valid reason and with an exemption certificate.
Shops and services, including public libraries, are open but must be closed at 6 pm, but bars, restaurants, cinemas, theatres, museums and gyms remain closed.
Employees must work from home where it is possible to do so.
"If the level of this variant were to increase significantly and we followed an English trajectory, a lockdown would probably become an absolute necessity," Véran told the French Senate's Law Commission.
The new variant currently represents around 1.4% of the total daily COVID-19 cases in France, according to a recent study that looked at all positive PCR tests.
The French government is pinning high hopes on vaccines and will be able to vaccinate 70 million people by the end of August "if all of the vaccines ordered are approved by European and global health authorities," Véran told TF1 television channel in an interview on Thursday after his comments to the Law Commission.
"People aged 75 and over who are impatient to be vaccinated will be before the end of March," he added.
The French government saw criticism in the first days of its vaccination campaign with people saying it was slow off the mark.
Initially discovered in southern England, the new, more contagious variant is raising concerns in the international community that it could cause health systems to become overwhelmed.
The UK is currently facing major difficulties in its hospitals, and on Wednesday recorded 1,820 more daily deaths, which is a new daily record. "This will continue because what we are seeing is the result of the new variant," warned Prime Minister Boris Johnson.
The four countries of the UK are currently subject to tight lockdown restrictions to combat the surge in cases.
While schools across the UK remain closed to most pupils, France has kept all schools open from nurseries to secondary education facilities, but university lectures are being held by videoconference.
President Emmanuel Macron warned students on Thursday to expect COVID-19 restrictions to remain in place for much of the remaining academic year.