The trouble for Johnson: striking a deal with Europe is one thing, winning over MPs quite another

The Brexit negotiations are like one of those seesaws that spins round and round as well as tipping up and down. Not only does the British government have to reach agreement with the EU, Boris Johnson also has to persuade the House of Commons to back any deal. And the problem has always been that the more the prime minister tips in one direction, with a compromise that pleases Brussels, the harder it is to secure the endorsement of the Conservative hard Brexiteers and the Democratic Unionist Party. At the same time, tilting towards the Eurosceptics sets the seesaw spinning away from Labour MPs.

Even if Johnson does get a deal at the European Council this week, the challenge to get it through parliament will be immense. The numbers are very tight and the prime minister will need every vote he can get to succeed where Theresa May failed. As he told Tory MPs on Wednesday: “The summit is not far but at the moment there is still cloud around the summit.”

The DUP, with its 10 MPs, is critical. Johnson suggested to the cabinet that he hoped Arlene Foster’s party would be on board, but there are reports of splits with Nigel Dodds, the party’s leader at Westminster, who is said to be more suspicious of the prime minister’s plan. When Tony Connelly, the well-connected RTE Europe Editor tweeted that the DUP had “accepted” the latest proposals on Northern Irish consent and so there was “optimism a deal can now be done,” Foster almost instantly tweeted that it was “nonsense” and “discussions continue.”

The Eurosceptics in the European Research Group will take their lead from the DUP, who they see as the guardians of the Union. They too are divided over how willing they are to compromise and they may not vote as one. Some are, though, more willing to consider supporting an agreement struck by a Brexiteer prime minister than they were to endorse the deal brokered by his predecessor. Jacob Rees-Mogg described May’s proposals as “cretinous” but now he is in the cabinet and insists he can “trust” Johnson because he led the Leave campaign. “There's a line from Churchill saying that he often had to eat his words and he found it to be a very nourishing diet—and that is something that happens in politics,” he said at the weekend.

Even if the prime minister shores up his right flank, however, he will be under attack from the left. It’s difficult to see many Labour MPs voting for a deal that is based on a harder version of Brexit than May’s withdrawal agreement. There are none of the protections for workers’ rights or environmental standards that had been promised by No 10 before in an attempt to win over the opposition. Johnson’s plan would also have a greater economic hit with implications for jobs and living standards. The analysis published by the UK in a Changing Europe think tank last week showed that the prime minister’s preferred Brexit would lead to a reduction of income per capita of 6.4 per cent compared to staying in the EU. The equivalent figure for May’s deal was 4.9 per cent and for a no-deal Brexit 8.1 per cent. One Labour insider said there would be no more than ten “at most”—and probably far fewer—who were willing to back the deal.

Johnson has also alienated the 21 former Conservative MPs who had the whip withdrawn for voting to block no deal. Most of them supported May’s withdrawal agreement and they are now divided over the prime minister’s plan. A handful of the most pro-European will almost certainly vote against it, but there is another larger block who have profound concerns both about the implications for the Union and the potential economic impact of the new proposal. They could make their support conditional on the deal being put back to the voters in a second referendum. “It’s not a good deal, the economic cost is likely to be high. It’s closer to no deal than May’s deal,” one former cabinet minister told me. “It may be that if this is the deal there is a case for supporting it only if there is a confirmatory referendum attached.”

Ironically Johnson’s deal may only pass if it is subject to a second plebiscite, the thing he fears most. That is of course precisely why the Brexiteers are now considering voting for a deal they would never previously have accepted. Their priority is to ensure the UK leaves the EU, they cannot risk putting the question back to the voters. They champion the “will of the people” but they are not at all sure that the people are still on their side. The seesaw tips and spins.