Buckingham Palace said that the Queen was not in the building when the man tried to get in, but would make no further comment.
More top news
ITV News Europe Editor Emma Murphy said Putin's team have pointedly claimed the Skripal poisoning crisis has boosted his victory.
Largely dry elsewhere tonight with a widespread frost and icy stretches
The so-called mini-Beast from the East has swept in, bringing with it snow, ice and strong winds.