Devastating argument from Policy Exchange this morning. Sir Stephen Laws QC – who was until 2012 the Government’s most senior lawyer on legislative and constitutional matters – says don’t assume that MPs could engineer a change to the law to postpone or cancel Brexit without persuading Government to acquiesce and participate in securing the change.

Attempting to change the law without the Government’s participation, he argues, could jeopardise fundamental constitutional principles based on centuries of history, especially if the Speaker dispenses with or ignores a rule that gives Government complete control over increases to public expenditure.

Sir Stephen Writes:

“If the Speaker chose to allow this rule to be dispensed with or ignored, that could have unpredictable, and potentially horrific, constitutional consequences. It could raise a question whether the Government would be entitled or might feel required to reassert its constitutional veto by advising the Queen not to grant Royal Assent to the Bill.

How should the Monarch react to such advice? The answer is not straightforward and the prospect of it needing to be considered in a real life political crisis is unthinkably awful. It is a sacred duty of all UK politicians not to involve the Monarch in politics. They have a constitutional responsibility to resolve difficulties between themselves in accordance with the rules, and so as not to call on the ultimate referee.”

If the Speaker and Dominic Grieve are going to vandalise the constitution and overturn established parliamentary conventions, don’t expect the government to just roll over. The Attorney General Geoffrey Cox will be studying this argument closely as no doubt will the Brexit sympathetic Queen. Bercow is only the Prince of Parliament, though he might not want to believe, the Queen still outranks him constitutionally. Grieve isn’t as clever as he thinks he is…