The Gaîté Lyrique theatre in Paris staged the conference, entitled Reinventing the welcome for refugees in France, on December 10.
It involved talks hosted by academics from top universities and Red Cross officials, and saw activists welcome in the migrants.
But when the conference was finished, the migrants refused to leave the venue.
Still occupied, the leftist theatre now faces going out of business after weeks without revenue from ticket sales, and has had to cancel all performances until at least January 24.
Its management said in a statement last week that the number of people taking shelter in the theatre is ‘continuing to increase’ and has swelled to around 300 people.
‘The sanitary conditions are deteriorating day after day and the teams are facing this situation alone,’ it said as it called for the local authorities to find a housing solution for the occupiers.
‘Although this occupation is forced, it is unthinkable for the Gaîté Lyrique to throw these people out onto the street in the middle of winter,’ the statement added.
When your heart is maybe, sort of, possibly in the right place sometimes but your head is up your a**. ABN