Only one thing is certain in Westminster as I write this, and that is that there will be a new Conservative leader and Prime Minister by the end of this year. So, who will it be?

First thing to remember is the current Conservative Party leadership election rules: Anyone can be nominated to stand, they don’t need a certain number of nominations like in the Labour Party so getting on the ballot paper is simple. That ballot paper can thus contain as many people who want to stand and will be whittled down to two by Conservative MPs, almost definitely by the time Parliament goes into recess on July 21st. The final two will then campaign around the country, until there is a postal vote by Conservative Party members (of which there are 150,000) to select the new leader. You cannot vote in the election if you weren’t a member three months before the final date – which stops “entryists” getting into the party to try to influence the result as happened with Labour.

Given this process, there are four possible directions the leadership election will go in my view:

First is to elect a “Brexit” Champion – meaning one of the leaders of the Leave campaign. This is most likely to be Boris Johnson, backed by Michael Gove (most likely as Chancellor). Boris should never be underestimated – this is a man who has a long track record of winning. He won the London Mayoral election in a left-wing City twice – with reports that he could walk through communities most hostile to Tories and be greeted like a hero. He also has a record as a ‘social’ Conservative, having taken plenty of centrist positions as London Mayor rather than being as right wing as lazy commentators insist.

Second is to elect a “safe hands” candidate from the Remain side who would be acceptable to those Conservative members who voted to Leave – i.e someone on the ‘wrong’ side the referendum who could still be trusted to fight for Britain in negotiations with the EU (as they have a history of Euroscepticism) – this is most likely to be Theresa May. May has achieved the impossible in politics – which is to remain as Home Secretary for six years, even successfully taking on the Police Federation without being pulled down. She may not have the ‘human touch’ of Boris, but she is calm, serious and would bring the party together more than Boris would.

Third is to elect a ‘working class champion’ from a modest background who encompasses what Conservatives like to argue their Party tries to achieve (even if their policies tend not to match this). After an Old Etonian Oxbridge graduate having to resign after a vote against ‘the Establishment’ – the Conservative Party may want to be careful to replace him with another one in Johnson. This is why Work and Pensions Secretary Stephen Crabb is one to watch: Crabb was raised on a council estate in Wales by a single mother. He has already called upon the party to change its approach and adopt ‘working class values’. He wrote this morning – “The referen­dum cam­paign highlighted deeply entrenched divisions in parts of Britain’s society which demands a One Nation response focused on impro­ving social mobility and break­ing down barriers to opportunit­y.” Crabb would need to be supported by a substantial, experienced figure, but there are plenty in the Party who might do that.

Finally, there is the ‘bolter’ from the blue (pun on Conservative colour intended). David Cameron was basically unheard of before he stood as leader in 2005. One to watch is George Freeman, who runs the 2020 group of about 30 MPs working on radical policy solutions. He apparently wants to use a leadership election to force the main contenders to accept their agenda, which is to adopt policies that will appeal to young people. Likely to team up with a female MP from the 2015 intake, Freeman will work at the very least to draw attention to the group’s views. From that platform, there is no telling where Freeman could go.

This brings me to an interesting initiative afoot at the moment according to Westminster sources. The MP Antoinette Sandbach is expected to table a motion at the next meeting of the 1922 committee (which represents back bench MPs) tomorrow, demanding that one of the two finalists in the leadership election should be a woman. Should this pass, it could mean that if only two female candidates stand and one comes out ahead in the first round of voting, that candidate would get a free pass into the membership vote. This would leave those who had voted for the winning woman to switch their support to any of Boris Johnson’s opponents in a bid to freeze him out.

My feeling though is that the Conservative Party members have been waiting for the chance to decide if Boris should leader the Party and may not be happy with their MPs if they don’t present him as one of their options. That said, polling of members rate Boris very highly as a person to have a beer with, but not as a person to run the country in a national crisis.

In case you are wondering why I haven’t mentioned George Osborne, he has no chance now of becoming leader. BUT he has always been interested in being Foreign Secretary and with his experience he would be useful in any Brexit negotiations. His support for a candidate will be important – before the EU referendum he had a long track record of running highly successful campaigns. Watch who he comes out in favour of.