The Sky News website reproduces some interesting remarks made by Tim Farron, the leader of the Liberal Democrats, yesterday. Defending the decision that Liberal Democrat peers in the House of Lords should seek to block housing legislation that would implement a Conservative manifesto commitment extending the right to buy to housing association tenants, Farron said:

I am going to argue that any party that got 24% of the eligible voters hasn’t got a democratic mandate. My view is I have to defend the communities of this country that stand to lose their affordable homes, their very heart and therefore to be ripped under … and of course we will use our power in Parliament to do that.

Farron’s proposed course of action would appear to be in clear breach of the Salisbury Convention, according to which opposition peers do not seek to block the legislative implementation of the governing party’s manifesto commitments. Along with the Parliament Acts 1911-49, the Convention is generally regarded as central to reconciling the House of Lords’ unelected nature with Parliament’s status as a democratic legislature. However, Farron said that the Convention is a “political stitch-up”, and that he would not abide by a “gentleman’s pact between the old establishment parties”. He went on to say: “I’ve signed no convention, the Lib Dems have signed no convention. My contract is with the British people to defend their interests.”

This is not the first time that the Liberal Democrats have threatened to withdraw their support from the Salisbury Convention. For instance, in 2005, Lord McNally, the then leader of the Liberal Democrats in the House of Lords, said that:

The Salisbury Convention was designed to protect the non-Conservative government from being blocked by a built-in hereditary-based majority in the Lords. It was not designed to provide more power for what the late Lord Hailsham rightly warned was an elective dictatorship in another place against legitimate check and balance by this second Chamber.

However, these concerns — unsurprisingly — faded away when the Liberal Democrats found themselves in government during the last Parliament. It is equally unsurprising that the Liberal Democrats should revive this line of argument now, particularly given that their near-annihilation in the general election reduced their representation in the House of Commons to just eight MPs, meaning that they presently account for just over one per cent of the total membership of the Commons. In contrast, the Liberal Democrats in the House of Lords boast 101 peers, which equates to just over 13 per cent of the total membership of the Lords. Given that Conservative peers, of whom there are presently 224, account for only 29 per cent of the Lords’ membership, it mathematically straightforward for the Government to be outvoted — and, therefore, for manifesto commitments to be blocked if opposition parties are prepared to rip up the Salisbury Convention.

Politically comprehensible though Farron’s position might be, it is not without difficulty. It is, for instance, paradoxical to argue that a party which was punished at the polls should rely upon its relative strength in an unelected legislative chamber so as to thwart the implementation of policies advocated by the most popular political party. More broadly, the argument that, on democratic grounds, the House of Lords should be used to thwart the wishes of the House of Commons is not an entirely straightforward one. Farron is doubtless correct when he implies that the first-past-the-post system distorts the popular vote, but it cannot be denied that, viewed in relative terms, the House of Commons can lay greater claim than the Lords to democratic legitimacy.

There are, of course, counterarguments. For example, the Liberal Democrats might well retort that the first-past-the-post system is unfair, and that their eight per cent of the popular vote in 2015 somehow justifies their representation — and the use of the muscle it gives them — in the House of Lords. And, as I pointed out in another post, it is at least arguable that the Salibsbury Convention may bite upon different forms of legislation in different ways and to different extents. This simply serves to illustrate the broader point that no constitutional convention is set in stone, and that the extent to which any convention is binding is necessarily a function of the normative strength of its rationale and of the relevant political actors’ resultant commitment to it.

It follows that for the leader of the Liberal Democrats to repudiate the Salisbury Convention is not necessarily “unconstitutional”. But at the same time it cannot be for the (self-interested) leader of one political party to determine what the convention is. Much will therefore depend on other parties’ reactions to what Farron has said and, in due course, to occasions on which the Liberal Democrats seek to block legislation implementing Conservative manifesto commitments. If other parties were persuaded to join in, so as to form a blocking majority in the Lords, one possible reaction on the part of the Government would be to resort to the Parliament Acts, although even relatively infrequent use of that mechanism would inevitably disrupt the Government’s legislative programme over the course of the Parliament. Another possible reaction would be to amend the Parliament Acts — which would not necessarily require the Lords’ consent if the amendments were themselves made using the Parliament Acts procedure — so as to render their use less disruptive, e.g. by reducing the Lords’ delaying power. The nuclear option, meanwhile, would be to dilute the opposition parties’ influence in the Lords by creating substantial numbers of new Government peers. Indeed, even the threat of doing that might suffice — as, ironically, it did a century ago when the Conservative-dominated Lords was at loggerheads with a Liberal-controlled House of Commons.

I have argued elsewhere that for all that the House of Lords gets a bad press, there is much to be said for (at least some aspects of) the present system. However, that system can remain workable only for as long as the delicate network of understandings concerning the role of the second chamber and its relationship with the Commons itself continues to work. Farron’s pronouncements in relation to the right-to-buy legislation may be no more than a flash in the pan. But it is just possible that they might prefigure the crumbling of the edifice of constitutional understandings that facilitate the uneasy — but arguably valuable — accommodation of an unelected second chamber within a democratic legislative institution. Time will tell.