The next Tory leader will be...

David Cameron's time as leader of the Conservative Party and British Prime Minister in coming to an end and the political manoeuvring to replace him is already underway.

To understand what is going on behind the scenes in the Tory party, you need to look back to Cameron's successful leadership bid in 2005.

Conservative leadership elections work like this: candidates put themselves forward, Conservative MPs have round of voting which eliminate one candidate at a time until just two are left, those two candidates are put forward for the all Conservative Party members to vote on.

There were four candidates on the first ballot in 2005, David Davis, David Cameron, Liam Fox and Ken Clarke. Clarke lost in the first round and Fox lost in the second by just 6 votes to Davis.

There has always been a rumour that some of Cameron's supporters voted for Davis in order to stop the more right-wing populist Fox from making it to the member vote - because they cynically believed that Fox would do better with the members than Davis.

Regardless of whether this is true or not, many grassroots Tory members see their leader as someone who was born out of political manoeuvring by their party's establishment and over the 11 years that have followed his election, they have become more and more divorced from the Conservative leadership.

Here is everything we know about the next Tory leader so far.

There are two things that will shape the future leadership race. The first is the EU referendum and the second is more of a finger-in-the-wind, it's time for a real shake up of the political order.

Let's start with the EU referendum. Unless the British public vote to remain in the EU by a landslide, the EU supporting Conservative party establishment are going to feel the wrath of their membership. The vast majority of Conservative party members, as do the chairmen of the Conservative constituency associations that represent grassroots Conservative members across the country.

Business Insider talked to the chairmen of several of the country's most active constituency associations and heard back the same thing, even from chairmen who aren't strongly anti-EU - their members feel alienated by their party's leadership and there is a general feeling that CCHQ , the Conservative Party's headquarters, want to curb the influence of the associations.

As Business Insider has pointed out before, if the UK votes to stay in the EU, the membership will be furious and will be in no mood to elect anyone who backed the Remain campaign. That will be especially true for anyone who was previously Eurosceptic, but changed their allegiance to the Remain campaign - which is exactly what several of the commonly cited candidates have done.

Let's start with them. First, Home Secretary Theresa May.

In theory May should be popular with the Tory grassroots and indeed, until recently she was. As Home Secretary she tried to present herself as tough on immigration, the human rights act and she has tried to put distance between herself and Cameron.

Then she came out in favour of remaining in the EU.

One of the best barometers of how Conservative Party members are feeling about potential leaders is the regular, if slightly unscientific polling carried out by the website ConHome. May's support has more tha halved from 21 per cent to 10 per cent since she came out for the Remain campaign.

It's the same story across the board.

Sajid Javid? The business secretary was very popular with Conservative members, but after coming out for Remain he has seen his support plummet. ConHome has puts his support at 5 per cent - down from 14 per cent.

The point here probably isn't so much that Javid and May are backing Brexit, but that having previously expressed eurosceptic views, they are giving the appearance that they have allowed their arm to be twisted by Cameron into joining the Remain campaign, possibly on the promise of receiving political favours.

This brings us onto the second big factor that will influence the change of leadership, the finger-in-the-wind anti-establishment thing that it going on in the western world at the moment.

Corbyn took control of the Labour party, not just because he inspired a new left-wing grassroots movement, - regular Labour party members were fed up of the politics as usual and voted in the radical candidate. The same thing is happening in the US with outsiders Donald Trump and Bernie Sanders.

The obvious winner from all of this is Mayor of London Boris Johnson. The conventional wisdom is that he is now the front runner. The bookmakers have installed him as favourite to replace Cameron, with odds of around 2/1. ConHome show him jumping in support from 14 per cent to 33 per cent following his decision to back the Leave campaign.

There's one problem though with Johnson: he has been accused of not being deeply committed to the Remain campaign but rather of seizing an opportunity to gain votes easily. A 2006 video of him in which he advocates expanding the EU and especially letting Turkey into the Union, has also resurfaced on Buzzfeed recently, which further underscores those claims.

So, if we discount Cameron's preferred successor chancellor George Osborne who, like May, has seen his popularity plummet, it leaves the field wide open for an outsider.

Business Insider has already pointed out that Fox, the man who came within a whisker of making the final ballot in 2005, could prove to be very popular with the membership. But there are also plenty of new faces among the Tory ranks. For instance, employment minister Priti Patel would tick almost all the boxes on an anti-establishment voters checklist.

As always with these things, it all comes down to timing. Cameron says he won't step down if he loses the EU referendum, but if he loses by any sort of margin he will almost certainly be forced out. Seeing as almost half of Cameron's MPs are backing the Leave campaign.

A 2016 leadership election could capture the zeitgeist of everything mentioned above and throw up a completely unpredictable leadership election.

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