As the first step to applying article 155 of the Spanish Constitution and revoking Catalan autonomy, the Spanish government this morning sent their Catalan counterparts a requirement that they clarify whether or not they have declared independence. The requirement, sent by email, sets a deadline of Monday for their response.
If Catalan president Carles Puigdemont replies that they have declared independence, the requirement sets a limit of next Thursday, 19th October to revoke the declaration.
This is a necessary step for the Spanish government before it can take a motion to apply article 155 to the Senate, where they would also have to specify what exact intervention they want to take.