According to The Sun's political editor, Tom Newton Dunn

Brexit

He notes that May is now plotting with senior aides to find a way to turn what is an imminent defeat tomorrow to something more significant. The change from a meaningful vote to a provisional one means she will be adding some caveats to the Brexit deal by proposing changes (that she may not get) to be added to it and then putting the whole thing to a vote.

The hope here is that if parliament can get behind that, then she at least stands a fighting chance in going back to Brussels to secure a last minute Brexit deal - with European leaders conceding and offering her the needed concessions - at the EU Summit on 21-22 March.

It sounds like a smart idea, but this is probably the last time she can kick the can down the road before we face a real decision on Brexit. I'm not sure if lawmakers would take too kindly with this though. Let's see how things play out in the coming two days.