As France prepares to ease its strict lockdown, a poll has shown that support for the draconian measures aimed at halting the coronavirus spread has dropped below 50% for the first time.

The French government will announce details of its plan to slowly ease restrictions across the country from 11 May, including the phased reopening of schools, on Tuesday. The proposals will be introduced to the Assemblée Nationale and put to a vote of MPs.

A survey published this weekend showed that less than half the population – 43% – now supports the maintaining of strict “confinement” measures, down eight percentage points from the previous week.

However, if the confinement ends, 82% want the government to make free masks available to the general population. The poll by YouGov for the Huffington Post showed more than three quarters of French people support the continued ban on sporting and cultural events and almost as many say workers should be urged to work from home if they can.

The reopening of schools remains divisive, with teachers concerned that they are being used as part of attempts to widen public immunity to the virus.

The government’s scientific committee has suggested school reopenings should be carried out in a “progressive and careful” way. However, in an earlier report the committee suggested “the risk of spread [of Covid-19] is greater in places of large gatherings like schools and universities, with it being particularly difficult to put in place barrier measures among the youngest pupils”.

It suggested keeping nurseries, schools, lycées and universities shut until September, in direct contradiction to President Emmanuel Macron’s decision to open nurseries and schools but not higher education establishments.

Last week, the country’s Academy of Medicine issued its recommendations for the return to school, insisting teachers should be given training in how to ensure pupils respect health measures. It advised having hand gel in all school lavatories, classrooms and entrances, with classrooms, canteens and common areas, particularly staircases and door handles, disinfected several times a day. The academy also advised that pupils should have their temperature taken before entering the school.

Those living in cities who use public transport to reach work and schools are also worried about how social distancing measures will be maintained if they are expected back at their jobs.

It has been suggested the government will make wearing masks on public transport obligatory, but it has failed to explain where the masks will come from or how they will be distributed. France’s Sunday newspaper Le Journal du Dimanche (JDD) reported an internal note from the junior economy minister Agnès Pannier-Runacher, which stated: “The national weekly production and imports [of masks] is still not enough at this stage to fully cover the need”.

The note suggested there may be enough masks by 18 May, one week after the end of lockdown begins.

An Ifop opinion poll for the JDD showed confidence in the government’s handling of the health crisis, that reached a high of 55% in March, had dropped to 39%.

Frédéric Dabi, Ifop’s director, said Macron’s national address on 13 April had brought a boost in popularity but since then “concern about the return to school and the summer holidays have worsened”.