One study of social media in March found that 'left' and 'liberal' politics appears to be the dominant force on Twitter. Other studies, such as this survey by YouGov, have shown that newsfeeds on Facebook lack right wing sources. In contrast to this, Facebook pages for right wing and conservative groups have the highest amount of activity and page 'likes'.
Moreover, targeted advertising was used to great effect in the 2015 election by the Conservative Party, who (according to the Electoral Commission) spent more than £2 million on Facebook advertising.
Likes and follows
Among mainstream political parties, the left is ahead of the right on Twitter followers, and the inverse is true of Facebook.
A ‘Like’ and a ‘Follower’ do not guarantee support, and often simply imply you’re willing to see their posts on your timeline. It does not show how many people on Facebook have ‘hidden’ posts from a party on their newsfeed, or how many Twitter users have ‘muted’ the parties tweets.
However, including the group Britain First, shows how the popularity of Westminster parties is relative.
So trending topics such as 'cost of tories' can be expected, given the left's influence on Twitter.