Gormley: Why Mr. Scheer's trip to London is so impolite

I wonder: What’s the polite way to respond when an opposition leader meets with United Kingdom officials about a post-Brexit free-trade deal several months after the prime minister met with United Kingdom officials about a post-Brexit free-trade deal?
Are we to thank Mr. Andrew Scheer for belatedly doing that which he was not elected to do and that which was already done by the man who was elected to do it?
Are we to hope that a trusted loved one will pull him aside and tactfully explain t