Now parliament must produce a Brexit plan

The promise of Theresa May’s government has been that Brexit will allow Britain to take back control of its affairs. Ironically, the prime minister has now all but lost control of the shape of an exit deal with Britain’s European partners. With the clock ticking towards the March 29 deadline it now seems more likely that parliament rather than Mrs May’s government will choose the terms of departure.

The House of Commons is due to vote on Tuesday on the government’s proposed settlement with Brussels. All the signs are that it still faces the prospect of defeat. After the vote was postponed last month, the EU27 offered assurances about controversial post-Brexit arrangements on the Northern Ireland border with the Irish Republic. The concessions have failed to win over significant numbers of those MPs opposed to the deal.

Mrs May’s authority was further undermined this week after an alliance of opposition and rebel Conservative MPs inflicted two defeats on the government. The second of these undercut decisively Mrs May’s strategy of “running down the clock” in the hope that the threat of a disorderly Brexit would eventually persuade MPs to fall into line. Now, if her own plan is indeed defeated, the prime minister is obliged to bring forward within days new proposals to prevent Britain crashing out of the EU without any agreement.

The imposition of this timetable, which marked a significant constitutional shift in the balance of power from ministers to parliament, provoked an angry reaction from committed pro-Brexit MPs on the Tory side. They accused John Bercow, the Commons Speaker, of displaying pro-European bias in changing parliamentary rules to allow the vote.

Though a controversial figure, Mr Bercow in this instance was right to break with precedent. These are extraordinary and dangerous times in Britain’s political life. The design of Brexit — how far it marks a sharp break with the EU or seeks to preserve economic and political ties — presents Britain with a momentous decision. Parliament should not be fettered by procedural niceties.

Given Mrs May’s failure to win over a majority of MPs, the transfer of authority to parliament was anyway inevitable and necessary. If Brexit is about reclaiming sovereignty, Brexiters cannot complain when the Speaker asserts the sovereignty of parliament.

The mistake, however, would be to assume that parliament will necessarily come up with a neat substitute for the prime minister’s plan. If most MPs oppose a cliff-edge Brexit, it is less obvious what flavour of Brexit would win the support of the Commons.

Mrs May has treated Brexit as the property of the Tories and its Northern Ireland allies in the Democratic Unionist party. The Labour leader Jeremy Corbyn has similarly opted for the pursuit of narrow political advantage over an effort to build consensus. This leaves deep divisions in both parties as to the best outcome. Some advocate continued participation in the EU customs union, others membership of the European Economic Area, and others still a second referendum.

So two more steps are required of the prime minister if her deal is defeated. The first is to signal a willingness to seek an extension by the EU27 of the Article 50 process to accommodate any proposals on which parliament can agree. The second to make time for debates and votes designed to indicate where majority opinion lies. Parliament, with the help of Mr Bercow, has indeed taken control. It is for MPs of all parties to show they can exercise that authority in the national interest.