Eurostar passenger carries stranger’s postal ballot from Paris to London

Moritz Hauschulz was able to deliver Lawrence Cheung’s vote to a polling station in his marginal London constituency. Photograph: Guardian Community

If the swing constituency of the Cities of London and Westminster is won by a single vote, it may all be down to one man who was not even eligible to vote himself.

Moritz Hauschulz, a German citizen living in London, was about to board a Eurostar train at the Gare du Nord in Paris on Thursday morning when he was approached by stranger clutching an envelope.