Alex Morton is Director of Policy at the Centre for Policy Studies, and was a member of David Cameron’s Downing Street Policy Unit.

If there is one thing that can still unite the Conservative Party, it is the belief that Jeremy Corbyn should not – must not – become Prime Minister. But how to stop that?

We are now nine years into Conservative or Conservative-led government. In order to block Corbyn’s path to power, the next election would be the fourth in a row where the Tories would need to win, or at least be the largest party.

This year will be difficult even if Brexit is resolved

In meeting this challenge, there are two strategic problems the Tories face – one specific and one general.

The specific one is that the Tory voter base is currently largely being held together by Brexit. Polls show the party steady at just under 40 per cent – no mean feat. But once a particular version of Brexit is decided on, or perhaps just arrives, at least some of those voters, even if a minority, are likely to feel deflated. At that point the Tories risk slumping in the polls – either by a little or potentially by a lot.

This means that the Party will need to offer some positive reasons to be a Conservative voter and supporter – to unite around a future prospectus. Voters are, as all the polling history shows, less likely to support parties they see as divided. Already 69 per cent of people think that the Conservatives are a divided party, according to Opinium. They are now seen as more divided than Labour – despite the fact that Jeremy Corbyn has been directly voted against by the overwhelming majority of his MPs.

Labour will also find it easier to ride out the storm this year than the Conservatives, due to the simple fact that they are not in government. While there may be a few who will turn against Corbyn if he never backs a second referendum, Labour will continue to be able to largely pretend to be all things to all people. They have been able to hide their divisions, and somehow have got away with continually falling back on the line that “nothing should be off the table”. Labour may well eventually have to come down on one side or the other, but even if they do, the harm this will do to them will be far less than to the Tories – after all, the Tories are in power, and Governments are held responsible for whatever occurs in a way that is simply not true for Oppositions.

The centre-right is in severe difficulty across the West

There is also a more general problem. Across the West, centre-right parties are under severe pressure (as indeed are centre-left). In many countries we have seen their collapse (eg France and Italy). Even countries that have fairly high levels of economic growth (at least relative to others, if not historically), such as Sweden and Germany, are seeing their traditional centre-right parties struggle.

Only a small handful of leaders have managed to be successful, and lead their parties to electoral success, most notably Sebastian Kurz in Austria and Mark Rutte in Holland. Those who have succeeded have largely done so by reinventing their parties for the populist era while remaining within the boundaries of the mainstream.

What all this boils down to is that not only will the Tories have to try to revise and revive their policies and platform after a fairly long spell in Government, but do so at a time when the centre-right in general is struggling to win elections and carve out a successful niche.

Moreover, this is all happening against a revitalised left rather than the divided left that is seen in many places. Yes, Labour are struggling now over Brexit. But once it is over, things are likely to become easier for Corbyn, since Brexit is the one issue that fundamentally divides him from his base of adoring followers.

The Tories need to be able to talk about policy, not personality

If the Conservative Party wants to defeat Corbyn, then it needs to renew itself. The Government’s time and effort have – the NHS aside – been largely and increasingly consumed by Brexit.

Yet the Prime Minister’s acknowledgement to the 1922 Committee in December that she will not fight the next election raises a new problem: that everything becomes seen through the prism of the future leadership, rather than the future of the Party.

Obviously it is true that policy and personality are intertwined. But it is hard – for example – to have a frank discussion about what post-Brexit immigration policy might be, because if you take a position on how far we should prioritise non-EU high skilled immigration, or whether we should scrap or actually enforce the ‘tens of thousands’ figure, it is seen as being about whether you back Johnson or Javid or Hunt or Raab.

The media obviously plays into this. An easy way to write a story is to call up sufficient numbers of key people and goad them into saying something less than wonderful about their colleagues. If you can’t get something out of ministers, then their allies will do. There is always someone willing to answer a journalist’s call.

There needs to be space in British politics – and within the Conservative Party – to have a robust debate about the future of the country without it being seen as just as about positioning between potential prime ministerial candidates.

It is true that the political debate is becoming very bad tempered – and it is unlikely to become less so over the coming months. Brexit has already weakened the ties that bind the Conservative Party together. But the real crisis will occur if Conservatives, and those in the wider conservative movement, end up going into battle against Corbyn’s far-left ideas without a compelling policy vision of their own.