Theresa May has come in for something of a royal public thrashing over the last two years. Humiliated by Jean-Claude Juncker and Donald Tusk in Brussels and by members of her own Cabinet and intransigent parliamentarians at home, not to mention her perpetual roasting in the media, one might be forgiven for thinking that the Prime Minister is solely responsible for the mess that we find ourselves in precisely 2 years down the line from the ill-advised and premature triggering of Article 50. Indeed, after her admittedly tin-eared Downing Street rebuke to MPs, the SNP’s Westminster leader Ian Blackford and the Labour leadership have repeatedly berated the Prime Minister’s handling of Brexit, seeking to place responsibility for our failure to leave the EU today with a deal in place entirely on her incompetent choices.

It is true that May has been a worse than poor leader during a time of international diplomatic and domestic constitutional crisis – precisely the sort of time when inspired and visionary leadership is most required. She was wrong to concede to the EU’s timetable for negotiations in the first place (money and backstop now, actual trade deal later), and she should never have allowed EU demands over the Irish border to dominate all aspects of the debate. During constitutional wrangling over “maximum facilitation” and “alternative arrangements”, crucial months were lost in what is – without offence to Unionists – a sideshow.

She has never believed in Brexit; when defending its cause at the dispatch box she repeats her over-rehearsed line again and again, that she wishes to “honour the referendum” but “in a way that protects jobs”. Translation: “I know it’s terrible but we have to do this. I’m doing it the least bad way”. Her rhetoric about “delivering Brexit” has always lacked any positive vision for what Brexit might involve, or what might actually be delivered once the turmoil of the withdrawal process is finally over. As it were, she has always been concerned that the package arrives but has never really shown much interest in its contents, or the opportunities it might bring. As her former chief of staff Nick Timothy recently confirmed, she has always seen Brexit as a damage limitation exercise.

Most fatefully of all she erred in summoning the General Election of 2017. This squandered her majority and exposed Britain to the manoeuvres of hostile EU negotiators who knew she lacked command of her own parliament in Westminster and as such felt emboldened to push her around.

However, she cannot and must not bear the full brunt when the historians come to perform their autopsy. The voting behaviour of many MPs has been bewildering over the course of the Meaningful Vote saga, to say nothing of the circumstances in which the merry-go-round we’re currently witnessing came about, though I’m looking in the direction of Dominic Grieve.

The hard-Brexiteer European Research Group in Parliament (led by Jacob Rees-Mogg and Steve Baker) has received a lot of flak for its refusal to support the Withdrawal Agreement, and there is justice in this criticism. Their reading of the Agreement and Political Declaration is in many cases faulty – many think they commit us to some kind of permanent customs union (they don’t), many think we will still be participating in the political institutions and subject to the European Court of Justice (we won’t), and some even seem to think that the backstop is the intended final state of relations (there is some alarming language about this in the Political Declaration, but on closer analysis this refers only to tariffs and not to customs tout court).

Their concerns about the Union and being trapped in the backstop are genuine, but the Attorney-General’s advice that these associated risks are much diminished by the supplementary Strasbourg documents is sound, as is Downing Street’s warning that the far greater risk is that Brexit is stopped altogether. The likes of Boris Johnson endlessly call for a change of direction in favour of a “Canada-style Free Trade Deal”, but they fail to recognise two things: first, that such a deal is in fact possible within the scope of the Political Declaration; secondly this (desirable) end point cannot even begin to be negotiated until the Withdrawal Treaty is ratified by both sides. As a matter of EU law a codification of final future relations cannot be made legally binding while we are still a member state. We have to leave first, negotiate a trade agreement later. So much for the Brexiteer rebels.

Less media commentary has focused on the other side, however. Whether it’s through the Cooper-Boles hijacking of the Order paper, Letwin’s indicative votes or the outrageously partisan decisions of the Speaker, the Remain caucus within Parliament has been doing everything within its power to stop Brexit or to water it down out of existence.

The fact that the majority of Remain-backing MPs consistently vote down the deal is now taken for granted, but why? Were over 80% of them not elected on manifesto pledges of honouring the referendum in 2017? That being the case, why are we seeing such high numbers voting to revoke Article 50 or for a second referendum in the amendment votes before the House? The Independent Group (TIG) are not even voting for the “soft-Brexit” options of the Norway option or a customs union; for them only a second referendum is enough. Of course, MPs must vote according to conscience, but it cannot be forgotten that overwhelming majorities in Parliament voted to trigger Article 50 and for the Withdrawal Act in 2017 and 2018, respectively.

There is a broader constitutional point here, too: the “meaningful vote” requirement of the 2018 Act has placed the UK in an absurd position of having the legislature dictate the terms of a treaty negotiation that in reality has to occur between two governments, not two parliaments. There is no reason to imagine that the EU will consider agreeing to whatever revised form of Brexit Parliament coughs up when it finishes off its indicative votes on Monday.

The most outrageous and under-reported behaviour, though, is that of Labour. When attacking the Government’s negotiating objectives, Corbyn and Shadow Brexit Secretary Keir Starmer consistently accuse the Prime Minister of imposing “artificial” red lines (ending free movement and taking us out of the Single Market and customs union). This is disingenuous; clearly failure to deliver on any of these would fall well short of implementing the declared goals of the Leave campaign – namely regaining control of borders, laws and money.

Labour have repeatedly said that they support “a customs union” (but not “the customs union”?), “full access to the Single Market” (without being in the Single Market?), are against the backstop without having any actual objections to it, attack the possibility of reduced workers’ rights and environmental standards but then oppose the PM when she guarantees them, and then after all this they lambast the Government for its failure to get the Withdrawal Agreement through the House – yes, Jeremy, it’s you that keeps whipping your MPs to vote it down. Their Six Tests were designed specifically to me unmeetable, thus creating a supposed justification to vote against anything the Government could agree with Brussels. The majority of Labour members are still sheepishly obeying the whip, apparently caring more about being perceived as Tory collaborators by the far-Left leadership than the very real possibility of frustrating the referendum or facilitating a No Deal.

The Opposition has remained true to form by declaring that it will refuse to vote today for the Withdrawal Agreement on its own, sans Political Declaration. But this has been the one part of May’s deal Labour does not have any official objection to (it deals only with citizens’ rights, money owed, the transition period and the Irish backstop). Indeed, when quizzed by Father of the House Ken Clarke on the reason for opposing the Agreement, Keir Starmer was unable to answer; his party’s objection has always been to deficiencies in the Political Declaration alone. Now the chance to vote for one and not the other is in front of them and they still won’t budge.

Furthermore, Labour has repeatedly committed the same fallacy as the “Super Canada” ERG diehards – namely, not grasping that the details of the future relationship cannot yet be fixed. Corbyn continually pinpoints failure to negotiate a permanent customs union as the only substantive criticism of May’s deal he can think of, but (just like a Free Trade Deal), this is impossible until the actual Withdrawal Agreement is on the statute books. That’s the EU’s insistence, not ours.

It is indeed the job of the Opposition in our parliamentary system to oppose; it is thus that governments are held to account. But these are extraordinary times when the sort of unity that generates wartime national governments is needed. Labour refusing to vote for the bare-bones Withdrawal Agreement – all the elements of which are essentially a legal necessity for any form of future deal – is simply not good enough. They are seeking to exploit the parliamentary arithmetic to paralyse the Government and cause a General Election in the hope of seizing power and implanting Corbynist rule. And it’s the Leader of the Opposition who accuses the Prime Minister of putting party before country.

May has been the wrong Prime Minister at the wrong time, and her mistakes are legion – and should not be overlooked. But Parliament’s role in all of this has been the chief cause of the Government’s gauntlet of woe in the Commons over recent weeks. Whether it’s through lack of understanding of the Withdrawal Agreement, refusal to face facts over the backstop, belief that parliamentarians can do Brexit a-la-carte, a concerted effort to stop the whole thing in the style of TIG and the SNP, or willful and culpable obstructionism by Labour, there has been a collective failure of responsibility.

Wednesday’s indicative votes proved that there is no majority for anything else, and minority views in the House must accept that they are a minority. Without the Withdrawal Agreement approved on both sides, the next phase of negotiations will simply not happen. MPs must back the deal.