Lord Hague:

Any minister who walks out at Chequers would show they were not fit to hold office in the first place

An observer might be forgiven for thinking that the Conservative Party now consists entirely of two factions struggling for advantage in the furious arguments over Brexit. Two weeks ago it was Dominic Grieve and MPS more hostile to leaving the EU who threatened a major revolt. This week Jacob Rees-mogg and the keenest Brexiteers are threatening all-out rebellion, while suggestions of resignations by ministers who campaigned to leave the EU are commonplace.

In fact, like any mature governing party, the Conservatives largely consist of a vast sensible middle. This middle comprises ministers who run departments without mishap or crisis; MPS who toil away so the next Tory government can be elected; councillors who recently saw off the Corbyn Momentum hordes with efficient local administration; and activists who expect their representatives to stick together, like they do.

They get on with their jobs without threatening to bring the house down every couple of weeks. On Brexit, they were on either side of the referendum but think the result must be honoured and the nightmare of fighting out the whole issue again avoided at all costs. They deeply dislike naked manoeuvring to become the next leader. And, if I might presume to try to speak for them as a former party leader, they would want to say a few things to the Cabinet before it meets on Friday to try to agree what it wants.

First of all, the time for agreeing a policy together is long overdue. Continued division is now worse than any of the options causing it. It is allowing the European Commission to sit back, make zero concessions and prepare to impose its own terms on the UK in the absence of any alternative proposals. This is meant to be a Government negotiating a momentous international agreement, not a debating society that has forgotten to impose a time limit on speeches.

Second, any minister who chooses this moment to quit because they don’t like what is agreed will show they were not fit to hold their office in the first place. That very difficult compromises would have to be made was utterly obvious as soon as last year’s election results pointed to a minority government. Flouncing out, just when the going gets tough but when the EU Withdrawal Act has been successfully enacted, will look like evading responsibility for choices that were inevitable, just when important progress has been made.

Third, if there really is on the table an idea that allows an independent trade policy, keeps an open border with Ireland and means minimal friction at customs for worried manufacturers, grab it with both hands. The concerns of businesses like Airbus and BMW cannot be dismissed. Nor should the Irish border issue be depicted as an irritating inconvenience that prevents a more ideal Brexit from being designed – every minister who advocated leaving the EU, or now supports it, has a responsibility to help find a solution that works for all parts of the UK.

Fourth, and most crucially, everyone threatening Theresa May with chaos, revolt, resignations, and a leadership election if she doesn’t do as they wish needs to think carefully about what might be the consequences of their actions. A vote of no confidence in the leadership called on this issue would in all probability rally the sensible middle to the Prime Minister. Even if it didn’t, any new incumbent would face exactly the same negotiating choices and arithmetic in parliament.

Such arithmetic is what any government has to live with. When we negotiated the coalition in 2010, we had to ditch some of our ideas, such as abolishing inheritance tax, in order to secure the overall prize of implementing a viable economic plan. This is a parallel situation – if ardent Brexiteers push too hard they will end up without their main objective. If there is no agreement this week on a plan for customs arrangements, the Commons will be much more likely to vote in the near future to stay in the customs union in its entirety. The choice is either to back a compromise plan now or to end up with a more watered-down version of Brexit that would be forced on ministers anyway.

More dramatically, a leadership crisis would extend the paralysis in the negotiations, play into the hands of the EU and even increase the currently small chance that we never leave the EU at all. If Conservatives don’t look as if they know how to deliver on the result of the referendum, public enthusiasm will be eroded and the growing pressure in the Labour Party to support a second referendum will intensify. That way lies the deepest and most bitter national division for generations, and it is the responsibility of a governing party to avoid it.

For all these reasons, when ministers start sipping their coffee at Chequers on Friday morning they should tell each other that they will not open the way to such bitterness, nor embarrass their party or undermine their administration as incredibly difficult talks with the EU proceed, and as the president of the United States arrives next week. They should remind each other that they have to live with the result of the last election as well as fulfil the outcome of the referendum, and they have a joint responsibility not to abandon a policy in which every difficulty so far has been entirely predictable.

Those ministers who have chafed and longed to get out of the EU should tell themselves they are now near their objective. Key laws have been passed. The planned exit is less than nine months away. It would be ridiculous to endanger it all over narrow differences on customs procedures. Now it is best to focus on ensuring some of the upsides of Brexit can be secured: an immigration policy that can bring in talent but insulate Britain from the wider crisis that will engulf the EU, and sufficient freedom in economic policy to allow ideas such as freeports and financial services regulation to be decided on in the UK, not Brussels.

Of course, they would argue these issues are all connected, and they are. But if they walk away this week or prevent agreement, they will be splitting their party to their own disadvantage. The big, sensible middle looks to all of them to think carefully, find agreement, and remember how far they’ve come.