As Jeremy Corbyn continues his seemingly unstoppable march on Brewer Street – now with three of the five big unions having rallied to his banner – many Conservatives are little short of gleeful.

This is not least because of the impression that his rise is being fuelled by tens of thousands of hard-left entryists from the Greens, Communists and sundry other parties and sects, so beguiled by the promise of backward-looking doctrinal purity that winning the 2020 election is almost an afterthought.

Yet before the Tory family gets too pleased with itself, we should remember that we are not above such spasms: in the years after 1997 the history of the party is one of a wilful refusal to confront the compromises necessary to win.

Whilst currently in an unexpectedly strong position, the EU referendum risks re-opening those wounds, and in the aftermath of that we face both a slew of selections for the general election and almost certainly a leadership contest.

So it’s worth considering the question: could outside forces hijack our democratic processes as they have Labour’s?

There are certainly those who might wish to do so. UKIP may be larger and more potent than the Greens and sundry sects and micro-parties of the far left, but some Kippers could still favour entryist tactics, whether they be People’s Army loyalists hoping to destroy a rival or former Tories trying to ‘reclaim’ their old party.

There are also left-wingers who might wish to lumber us with an unelectable candidate in much the same spirit as Tories for Corbyn. Indeed, one of the criticisms of T4C is that breaking the gentlemen’s agreement on internal democracy makes such retaliation more likely.

However, a critical difference is that unlike the Blair years – or Labour now – our members are not reeling from rejection and defeat. The mass of the membership seems much less likely to embrace a candidate too far from the mainstream, and regardless of infiltration Corbyn’s campaign rests on his undeniable appeal to a huge chunk of the Labour membership.

The first test is the party’s contest for the London Mayor candidate. The final shortlist of four will be put to an open primary, with an electorate comprising both members and anyone on the London electoral register who registers as a supporter and pays a £1 fee.

The Party is aware of the danger – one of the upsides of the Corbyn phenomenon may have been that the risk of undue influence in party selections has been put under the spotlight. Whilst we don’t know what specific measures the party has in place, several risk-mitigating factors suggest themselves.

The first is that there simply isn’t a Corbyn-like candidate on the shortlist. However voters might feel about the options individually, none of them is a hard-line cliché and serial rebel on the level of the MP for Islington North.

Political opponents sufficiently partisan to countenance entryism might also balk at having to hand over their name, address and credit card details, not to mention that precious pound, to the Tories.

London is also a much more manageable area to police than the entire country – CCHQ is unlikely to need the fifty full-time officials Labour has reportedly drafted in to sift its tide of new recruits, whose salaries must surely be eating up much of the £3 fees said recruits are bringing in.

However, the efficacy of such policing is surely limited. Whilst some of those Tories for Corbyn were considerate enough to state the destruction of the Labour Party as their motivation for joining – and lost their vote in the process – it seems reasonable to assume that anyone willing to engage in entryism is willing to lie about their intentions to CCHQ.

In contrast, our leadership election seems much less susceptible to outside influence. Whilst both parties use MPs as gatekeepers by requiring leadership candidates to secure nominations, the Conservatives only put two names forward to the membership.

This makes it almost unthinkable that a moment of complacency or indulgence might see someone slip through the net as Corbyn did, and there are no third-party actors like the unions with the funds and ambition to derail the party.

On the surface open public meetings to select PPCs seem more vulnerable, but they have their own advantages. Their lower profile makes it much harder to whip up interest amongst outsiders, and the tight geographical limitations on the electorate limit the potential for mischief.

If anything, the risk of infiltration ought to be a spur to associations to engage as many people as possible in the contest, in order to minimise the influence of troublemakers.

For all that, the single biggest factor helping the Tories is simply that the party isn’t in the dark place Labour is. The leadership is respected, if not adored, and the tranche of new MPs brought in at the last two elections is broadly considered to be of high calibre.

So long as the members and MPs keep their heads, there is very little that outsiders can do. Regardless of whether entryists end up pushing him over the line, Labour cannot deny that Corbynmania is a self-inflicted wound.