Further down the BBC story we are told:
Last year, Conservative housing spokesman Grant Shapps was targeted by hackers who broke into his YouTube account to post a message under his name saying the party could not win the Ealing Southall by-election.Nonsense.
The message posted under Shapps' name purported to come from a Lib Dem activist and said that the Liberal Democrats had no chance of winning.
Thanks to Bloggerheads for the graphic.
He also gives his explanation of how that message came to appear. You may think it more believable than the claim that someone hacked into Shapps' YouTube account, but I couldn't possibly comment.