BRUSSELS - The European Commission has no firm deadline for when Britain should make a formal proposal to break the deadlock over Brexit, but says it should be presented before a "milestone" EU summit on Oct. 17-18.

"If there are no precise dates being mentioned that is not a deadline because a deadline implies a precise date. In that case, as I have reiterated, every day counts," a European Commission spokeswoman said on Thursday.

"We mentioned the European Council in October as a milestone in our calendar so in order to properly prepare a European Council the sooner we make progress the better, but I don't have a precise date to give you," she continued.

(Reporting by Philip Blenkinsop) ((philip.blenkinsop@thomsonreuters.com; +32 2 287 6838; Reuters Messaging: philip.blenkinsop.thomsonreuters.com@reuters.net))