The House of Commons will today approve a motion with cross-party support for the Government to publish its long-awaited “plan for leaving the EU” before it invokes Article 50 of the Lisbon Treaty to kick-start two years of Brexit negotiations with the EU. In an apparent U-turn, Theresa May, who has been keeping her cards very close to her chest, agreed to disclose her Brexit plan.

Q: Why did Theresa May back down and accept Labour’s Commons motion?

A: The Government faced an embarrassing defeat after Labour tabled a clever, rather bland motion calling for proper parliamentary scrutiny of the Brexit process, while respecting the people’s decision to leave the EU and saying that the plan for leaving should not include material that could damage the UK in the negotiations. This attracted the support of pro-European Conservatives, who have become increasingly impatient with Mrs May’s refusal to spell out what Brexit really means. They claimed between 20 and 40 Tory MPs were ready to support Labour in today’s vote. Tory whips insisted the figure was nearer 12, but that still left the Government facing defeat. Rather than oppose the Opposition motion, the Government took the heat out of the vote by accepting it.

Q: How significant is Mrs May’s retreat?

A: Not as significant as the headlines suggest. She has not said how detailed her plan will be. It is unlikely to be a Green or White Paper and so may be rather thin and vague. Mrs May has offered something she would have had to do at some point --saying a little more about her negotiating aims, which she always intended to do when she invoked Article 50.

Q: What will be in the plan?

A: It will probably be a "motherhood and apple pie" statement repeating May's desire for the "best possible access" to the EU market while gaining "control" over EU migration. It is likely to say the UK must be free from the jurisdiction of the European Court of Justice, as the Prime Minister made that a non-negotiable “red line” at the Tory conference in October. But the plan might not go into whether the UK will remain in the EU single market or customs union in any detail, or tackle the sensitive issue of whether Britain might pay into EU coffers for market access. Ministers could argue that these matters should be left for the negotiations.

Q: Was it a victory for Labour to force Mrs May’s hand?

A: Yes, and a rare one too, although it may look more like a tactical rather than strategic victory when we finally see the plan. But Mrs May’s retreat is a sign that the Opposition has sharpened up its act since the appointment of Sir Keir Starmer as shadow Brexit Secretary.

Q: Was that the end of the Parliamentary game-playing?

A: No. The Government added an amendment to Labour’s motion saying Article 50 should be invoked by 31 March, Mrs May’s deadline. This was a clever attempt to challenge Labour not to block Article 50 and lock it into the Government’s strategy. Labour does not want to be seen to be thwarting the June referendum decision and so has accepted the Government’s amendment.

Supreme Court Brexit Challenge Show all 13 1 /13 Supreme Court Brexit Challenge Supreme Court Brexit Challenge People wait to enter the public gallery outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters Supreme Court Brexit Challenge Gina Miller, co-founder of investment fund SCM Private arrives at the Supreme court in London on the first day of a four-day hearing Getty Supreme Court Brexit Challenge A man waves the EU flag in front of the Supreme Court Getty Supreme Court Brexit Challenge Satirical artist Kaya Mar poses with two of his paintings in front of the Supreme Court Getty Supreme Court Brexit Challenge Pro-Europe protestors dressed as Supreme Court Justices stand outside the Supreme Court ahead of the first day of a hearing into whether Parliament's consent is required before the Brexit process can begin. The eleven Supreme Court Justices will hear the government's appeal, following the High Court's recent decision that only Parliament can trigger Article 50 Getty Supreme Court Brexit Challenge The eleven Supreme Court Justices will hear the government's appeal, following the High Court's recent decision that only Parliament can trigger Article 50 Getty Supreme Court Brexit Challenge Businesswoman Gina Miller arrives at the Supreme Court ahead of the first day of a hearing into whether Parliament's consent is required before the Brexit process can begin Getty Supreme Court Brexit Challenge Attorney General Jeremy Wright arrives at the Supreme Court in London EPA Supreme Court Brexit Challenge Protesters outside the Supreme Court in London, where the Government is appealing against a ruling that the Prime Minister must seek MPs' approval to trigger the process of taking Britain out of the European Union PA wire Supreme Court Brexit Challenge A protesters wearing a judge's wigs and robes stands outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters Supreme Court Brexit Challenge A protester holds up a placard outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters Supreme Court Brexit Challenge Pro-Europe protestors dressed as Supreme Court Justices stand outside the Supreme Court Getty Supreme Court Brexit Challenge A man waiting to enter the public gallery waves a European Union flag outside the Supreme Court ahead of the challenge against a court ruling that Theresa May's government requires parliamentary approval to start the process of leaving the European Union, in Parliament Square, central London Reuters

Q: Does that mean that the Commons will approve Article 50 in today's vote?

A: No. The Opposition motion is not binding. In any case, the question of whether ministers need parliamentary approval to trigger Article 50 is being settled in this week’s case in the Supreme Court.

Q: So is everyone at Westminster happy now?