Belgian Prime Minister Alexander De Croo considers it "possible" to organise "a few big festivals" in "the second half of the summer", like the electronic music festival Tomorrowland, his cabinet said on Sunday.

The details are to be announced Tuesday by the consultation committee, which brings together the federal government and the federated entities.

"One of the options considered is to grant access on the basis of the Digital Green Certificate", according to a source.

This European health certificate, with a QR code attesting that its holder has been vaccinated, has passed a negative test or is immune after being infected with Covid-19, is currently the subject of negotiations within the EU. The objective is for it to be in place before the end of June.

EU heads of state and government discussed it during the Porto summit held on Friday and Saturday, but not all agree on the harmonised pass.

Entrance to festivals would only be possible with tickets purchased in advance to allow tracking, and access would be limited to visitors from Europe and the UK.