"Qatar has received an invitation to the EU-LAS summit, which will take place in Egypt… The invitation received from Egypt breaches international protocol with its language and format", the source said.
According to the source, unlike invitations to other Arab countries, Qatar's invitation was not addressed to the country's leader personally and was not sent to Qatar's permanent mission to LAS but was forwarded to the Greek Embassy in Doha instead.
"The style of the message resembles that of a reminder of the summit and is inconsistent with an official invitation", the source added.
The source described Egypt's actions as "unprofessional" but noted that Qatar's permanent representative to the Arab League would, nonetheless, participate in the summit since Doha is committed to cooperation with its partners from the European Union and to common activities with other Arab states.
The two-day EU-LAS summit will be held in the Red Sea resort city of Sharm El-Sheikh.
In June 2017, Egypt became one of four Arab League members — Bahrain, Saudi Arabia and the United Arab Emirates — that broke off diplomatic relations with Qatar and imposed an economic blockade on the country after accusing Doha of supporting terrorism.