AS we commemorate the end of the First World War, it’s worth remembering a forgotten incident that occurred in April 1918. The last great German offensive had been hurled against the Allies on the Western Front. The French army had mutinied, leaving the Brits desperate for cannon fodder. The solution was to extend conscription to Ireland and send Irish farm boys to die in the trenches.

But at a special meeting in Dublin, held on April 20, the moderate Irish Nationalist Party voted to withdraw its MPs from the House of Commons as a protest at extending conscription to Ireland.

(Note: this was before the post-war election gave Sinn Fein, the Nationalists’ chief rival, a majority of Irish MPs and Sinn Fein’s own withdrawal from Westminster to set up an independent Irish parliament, Dáil Éireann.)

The Irish Nationalists were desperate to make a bellicose and blinkered Westminster understand it could not go on ignoring the wishes of the Irish people for an end to the slaughter. A parliamentary boycott was their nuclear option. By rallying popular support in conjunction with the local Catholic Church, the boycott worked. Britain refrained from implementing conscription across the Irish Sea.

Fast forward to Scotland in 2018: a snap General Election is called after Mrs May’s Brexit plan is voted down at Westminster. The SNP stands on a mandate to negotiate immediate independence if it wins a majority of Scottish seats. What then? Should the SNP MPs even bother to turn up at the (literally) rat-infested Palace of Westminster?

Much depends on who forms the next UK Government. It goes without saying that another Tory government will ignore Scotland, just like the current one. If there’s a minority Corbyn administration, the SNP contingent might be in a position to offer a DUP-like confidence-and-supply arrangement in return for independence negotiations. Such a prospect would militate against any immediate SNP boycott of Westminster.

However, a General Election any time soon is likely to leave most of Labour’s right-wing MPs still in place. They will imprison Corbyn in a political straightjacket – on Brexit, on the economy and especially on Scottish matters. At best, a Corbyn government might offer Scotland an agreed second independence referendum. Unless the SNP were willing to play political hardball, Labour is likely to ignore an SNP election mandate to negotiate separation. What then?

SNP MPs could stay at Westminster and employ disruptive tactics pro tem, to try and force the government of the day to accept the will of the Scottish people for self-determination. There is another

Irish precedent: that of Charles Stewart Parnell, the Nationalists’ leader in the late 19th century. Parnell adopted a tactic known as “obstructionism”. This aimed to bring all parliamentary business to a grinding halt until Westminster granted Irish Home Rule, or at least proved willing to negotiate.

Obstruction tactics included putting down endless amendments to Bills; making frequent (and long) interventions in debates; and raising countless points of order. This sounds innocuous, but Parnell and his Irish colleagues were prepared to put in long hours, day after parliamentary day, and deep into the night, for years on end, in order to bring Westminster to gridlock.

One of the most dramatic displays of Irish obstruction took place in July 1877, during the committee stage of a Bill to federate the different British colonies in South Africa, against the wishes of the local Boer population.

Parnell extended the debate by days, evading motions for his own suspension and clashing with the committee chair on numerous occasions. Worse, Parnell crossed a political line for the Westminster establishment by drawing too close a parallel between British rule in Ireland and Britain’s racist treatment of its colonies abroad. He quipped acidly that England had “annexed Fiji, then introduced the measles, and then taxed the people to pay the expense of the annexation”.

As a result, the Tory government announced immediate new procedural rules for debate. These made it easier to suspend members deemed obstructionist. Parnell struck back by intervening 16 times during the next committee session. He kept calling votes throughout the night which meant more than 200 Tory MPs were kept out of their beds, with only Parnell and fellow Irish Nationalist MP Frank O’Donnell in the opposition Lobby. A tireless Parnell kept the House sitting for a continuous 26 hours.

The story does not end there. Parliament continued to toughen its procedural rules, to ensure there would never be another Parnell.

The Speaker now has extensive powers over what amendments to call, which means the SNP is usually ignored. Debates are time-limited in a ruthless fashion. Yet from personal experience, I believe that a determined opposition group could still bring parliamentary business to a grinding halt. True, the parliamentary establishment would soon adjust the rules accordingly; so any premeditated obstruction campaign has to be punctuated and aimed at achieving a specific political concession.

SADLY, the Parnellites did not achieve Irish Home Rule. Partly this was because they split in 1890, ostensibly over Parnell’s affair with a married woman, but more a reflection of a deeper division between moderate devolutionists and those supporting outright independence. But mostly Irish Home Rule was thwarted because hard-line, Protestant Unionists in Northern Ireland set their face against any political accommodation with their fellow countrymen while cynical UK politicians were only too willing to accommodate Orange extremism in return for Westminster votes. Plus ça change.

Which brings us back to 2018. After a General Election, whoever wins will be obsessed with negotiating the next stage of Brexit. Scottish needs will be very far down the list of Westminster priorities. Which is why I believe the SNP must set down a marker in its election manifesto by declaring that – if it wins a clear majority of Scottish seats – we will take that as a national mandate to negotiate independence. The essence of the Irish experience is that you must get Westminster’s attention by fair means or foul.

Of course, Westminster is unlikely to accept Scotland’s democratic mandate without being pushed. This “push” might need to combine campaigns of mass civil disobedience north of the Border – say blockading Faslane, or refusing to pay the BBC licence – with obstructive tactics inside the House of Commons. In other words: no Scottish independence talks, no Brexit legislation goes though Westminster.

What if Westminster won’t respond? Do we withdraw? Or go on making speeches that only get reported on our own social media? I’m sceptical about a boycott. Being at Westminster is undoubtedly frustrating, but abstaining from political institutions is ultimately a futile gesture. It is always better to turn up and give Scotland a voice.

But equally, I don’t believe in reducing politics to the routine. That risks voters abstaining and MPs becoming careerists. Which is why I think the SNP should impose strict term limits on how long individual MPs remain at Westminster. And the party’s continuing presence at Westminster must to be tied root and branch to a specific strategy for winning independence – and soon. If we remain at the Palace, then we need to imitate the Irish obstructionist tactics of Parnell. If that makes them angry in the Commons tea room, excellent.