Observer says London polls show surge to the Lib Dems

Tomorrow's Observer reports the results of polls in three London constituencies: Kensington, Wimbledon and Finchley and Golders Green.

It says:

In all three, the Conservatives now hold narrow leads; in all three, the Liberal Democrats are close behind.

The paper goes on to explain that those polls reveal a similar pattern in all three seats

• Most Labour and Lib Dem supporters are prepared to vote tactically if their preferred party is out of the running.
• Labour supporters are willing to switch to the Lib Dems in overwhelming numbers – in all three seats by enough to give the Lib Dems victory.
• Lib Dem supporters tend to prefer Labour, but far less decisively. If they can’t have a Lib Dem MP, quite a few would vote Conservative, in each case by enough to increase the Tory majority.

Could it be that Brexit has forced the Lib Dems to adopt a core-vote strategy and that this strategy is bearing fruit?