The term 'stalking horse' is in the news this week with reference to a possible leadership challenge to prime minister David Cameron. The last time I remember 'stalking horse' being in all the papers was in the late 1980s when it referred to the Conservative backbencher Sir Anthony Meyer, who challenged Margaret Thatcher.
The original meaning (16th century) of stalking horse was an actual horse used on hunting expeditions. Hunters would hide from wild birds behind the horse. Later, a piece of canvas or material was given the name 'stalking horse'. The figurative meaning of stalking horse in the OED is: "A person whose agency or participation in a proceeding is made use of to prevent its real design from being suspected".
In politics, a stalking horse is someone who challenges the leader, but he or she is merely a front or figurehead. Usually there is someone much more powerful waiting in the wings who really wants the leader's job, but wants to keep his or her identity secret. Having a stalking horse allows the ultimate intended challenger to test the waters and see if there is a likelihood that party members will vote against the leader.
Stalking horses are usually obscure. I had never heard of Adam Afriyie before this week. In 1989 no-one had ever heard of Sir Anthony Meyer. In fact, he was so obscure that he was nicknamed a 'stalking donkey'. However, despite this, Meyer did get enough votes to convince Conservative MPs that there was a good possibility that Margaret Thatcher could be ousted, and Sir Anthony Meyer's action precipitated her downfall.