Andrew Gwynne said Labour had so far managed a "very clever" line on Brexit, but admitted that "could become a political problem" for the party.
Jeremy Corbyn has so far emphasised a flexible approach, with a spokesman for the Labour leader saying this week that it would be wrong to "sweep options off the table".
And Mr Gwynne hinted that the party could yet change tack if public opinion changes.
“We recognise that the country voted to leave. Whether public opinion shifts in the course of the next couple of years will be interesting to see," Mr Gwynne told an event organised by PR firm Four Public Affairs.
It's this last sentence opinion that worries me. I would have though Labour would want to shape public opinion rather than shape itself in response to it. Isn't that what politics is about, especially on the left? Surely it's not about working within the Overton Window but moving it? If not, what's the point? As it stands it seems that what Gwynne is saying is where the Mail goes Labour will follow. And that's pretty depressing.