It's Jeremy Corbyn's job to point out the damage Theresa May is doing by going to Brussels empty handed at this late, late hour

The Labour leader was right to upbraid the prime minister in the House of Commons today for the uncertainty over Brexit and cite the concerns of British business, from Airbus to BMW, about the possibility of a failure to reach any Brexit deal at all

The divisions in the government, and the prime minister’s weakness in overcoming them, are now damaging the national interest (PA)

The prime minister travels to Brussels for the European Council tomorrow, and still the fundamentals of our post-Brexit relationship with the EU have barely begun to be negotiated.

We have four months to go before the original deadline set by Michel Barnier, the EU negotiator, for agreement on the terms of the deal. That was to allow time for the convoluted ratification of the treaty by all 28 states, including the constituent parts of some federal nations, and the European parliament.

That deadline has slipped a little, with Mr Barnier mentioning November and some Brussels insiders talking of December. But the intermediate deadline of tomorrow’s summit looks as if it will come and go without any significant progress. Douglas Adams may have loved deadlines and “the whooshing noise they make as they go by”, but these are serious matters of national destiny.

It looks as if Theresa May has deliberately allowed this one to whoosh past in order to postpone the moment her cabinet has to make the difficult compromises required, not to reach agreement with the EU but with each other.

Thus we have the extraordinary sequence of an EU summit immediately followed by an intensive cabinet meeting intended to thrash out the UK government’s position. Instead of inviting her colleagues to an away day at Chequers, the prime minister’s country house, to agree a position in advance of negotiations, Ms May is going to allow an EU summit to slip past and only then try to decide what her government’s position might have been.

Her fellow EU leaders may be puzzled, but it is no skin off their noses. They have enough of more immediate concern to their national interest to deal with tomorrow and Friday. The Mediterranean migration crisis is more than enough to occupy them, even without their anxieties over the long-term health of the euro.

So Labour leader Jeremy Corbyn was right to upbraid the prime minister in the House of Commons today for the uncertainty over Brexit. He was right to cite the concerns of British business, from Airbus to BMW, about the possibility of a failure to reach any Brexit deal at all.

Theresa May’s responses were feeble. She told Mr Corbyn that he could not back business and overthrow capitalism, but politics has come to such a remarkable pass that, as our columnist Andrew Grice reports, some business leaders now say it “couldn’t be any worse” to have a government led by the anti-capitalist Mr Corbyn.

Mr Corbyn does not like pointing out personality differences in the cabinet but now it is his national duty to do so. The divisions in the government, and the prime minister’s weakness in overcoming them, are now damaging the national interest. Few secretaries of state hold their places in the cabinet on merit. Today, for example, Prince William did a better job than the titular foreign secretary in promoting a two-state settlement between Israel and the Palestinians.

Meanwhile almost all members of the cabinet appear to be auditioning continuously in the leadership hustings to replace Ms May.

This is no way to run a government. It is no way to run a vital national negotiation. It has come to something when business leaders say that Mr Corbyn could not do a worse job than Ms May in negotiating our departure from the EU.