Ms Davidson led the Scottish Tories into the 2016 Scottish election, where they doubled their number of seats, replacing Labour as the SNP's main opposition.
She campaigned to remain in the European Union, and previously said she would not back a no-deal Brexit.
A spokesman for the Scottish Conservatives said: "Ruth will make her position clear in due course. There will be no further comment tonight."
Ruth Davidson's Office have been contacted for a comment.