There has been a lot of press speculation about the next Conservative leadership contest in the past few days. Just in this morning’s newslinks we read that David Davis, the Brexit Secretary, may be emerging as a ‘unity candidate’.

But there’s one bizarre bit of chatter which, to those at all familiar with the Party’s leadership rules, is slightly bizarre: talk of a ‘stalking horse’ challenger.

Some background. The phrase really became prominent during the twilight of Margaret Thatcher’s administration, when the very liberal Tory backbencher Sir Anthony Meyer challenged the then-Prime Minister for the leadership. He didn’t think he could win, but hoped that once he’d tested the waters a more prominent Wet would step up. In the event, none did so.

How was a total unknown like Meyer able to challenge Thatcher? Because of a crucial difference in the Party’s leadership contest rules: back in the early 1990s, a would-be challenger only needed a proposer and a seconder to put themselves over the top.

That made challenges ridiculously easy to mount – and the rule has since been scrapped – but it also made relatively low-key challenges like Meyer’s possible.

Under the new system there is no space for a ‘stalking horse’. Triggering a leadership election requires a substantial revolt by the Parliamentary Party (the current threshold is 48 MPs writing to Graham Brady, the Chairman of the 1922 Committee). Any would-be bid to oust a leader must have already gathered significant momentum in order to get off the ground.

It isn’t entirely clear from the Telegraph article whether the MP quoted genuinely thinks that a stalking horse is a viable strategy or whether the paper has over-emphasised a natural comparison with Meyer’s bid.

If the former, it is difficult to see how a modern version of the tactic would work. Absent an actual challenge via the 1922 committee anybody simply saying they were challenging May would become a joke in short order. But once a contest is triggered then in ordinary circumstances then (in normal circumstances) the serious challenges would need to throw their hands into the ring before the rounds of MP ballots.

Is the idea to trigger a leadership election and then engineer it so that only a single, weak candidate stands against the Prime Minister? That’s surely risky: if the Brexiteers put up their ‘stalking horse’ but another, more serious candidate from another wing of the Party steps in as well, they risk losing the leadership without really contesting it.

The Party’s modern rules leave no space for stalking horses, and it currently seems very unlikely that May would stay once any leadership contest was triggered. If Tory MPs are serious about bringing her down, they need to spend less time at the history books and more with the Party rulebook.