As I write this on Monday evening, the House of Commons stands in uncharted political territory. Terra Incognita, as they used to say on the maps.

Backbench MPs have again taken control of the parliamentary agenda for "indicative votes". The Speaker has granted four out of eight tabled proposals to be voted on. These are a Customs Union; "Common Market 2.0" (a rebadged version of the so-called Norway option, which would mean membership of EFTA and the European Economic Area); a "confirmatory vote"; and "Parliamentary supremacy" (meaning a delay and then either no deal or the revocation of Article 50). The Labour party has said it will support Common Market 2.0. 

If any of these motions succeeds, on Wednesday there will be legislation, again drawn from the backbenches, to enact it. And if that happens, this country will be in an extraordinary place:  a democratically elected Government, elected on a manifesto commitment to deliver a Brexit which is outside the Single Market and Customs Union, and to do so in an orderly and agreed way, will find that policy overturned by backbenchers who have no corporate standing to do so. 

This is a group of individuals who have temporarily made common cause. They form no political party, they offered the electorate no policy at the last General Election, they have no collective mandate of any kind.  They have no executive capacity.  In no other respects do they act together.  After their policy has been adopted they will doubtless cease to act together at all.  They are in the purest sense a Parliamentary faction. 

For this reason, they lack the most basic ingredient of any proper parliamentary grouping or activity:  political legitimacy. 

Nor is any of these proposals acceptable on its merits. All are significantly worse than the Government's Withdrawal Agreement; the first two and the fourth breach elected manifesto commitments of the Government; the second presumes on a relationship with EFTA which may not be possible; the third is a disguised attempt to re-run the referendum, which would likely be disastrous. 

For these reasons I will be voting against all of these proposals tonight.  None deserves to succeed, and it may be that the adoption of one—or none—of them on Wednesday is enough to bring Parliament as a whole back to its senses.  On the ancient maps, parts unknown were sometimes marked with the phrase "HIC SUNT LEONES"--"Here are lions". So it may yet prove.