Tax credits are too big a story for the constitutional stand-off the Opposition is provoking to truly take centre stage. But the long-term consequences of this abuse of the Upper House will be more serious.

I’m a defender of the House of Lords. I believe that an expert, advisory chamber is a great benefit to law making, and that the absence of any democratic mandate is essential to the proper functioning of such an institution.

Senators, after all, would have their own mandates and thus feel entitled to pursue their own agendas. Gridlock – the unhappy consequence of American-style ‘separation of powers’ – would be the result.

But critical to the proper functioning of the upper house is the recognition on the part of peers of their limited role, and proper humility in the face of the democratic Commons.

Both Labour and the Liberal Democrats have signalled that their troops on the red benches are no longer willing to play by those rules.

It isn’t just tax credits, although that’s grabbing the headlines. Writing in today’s Times (£) the Viscount Ridley, a Tory peer, reports that Labour also plan to delay individual voter registration in the Lords in order to get a more favourable boundary review.

In short, using unelected peers in the Lords to gerrymander election boundaries for the Commons – behaviour which not only shows deep disrespect for the constitution but is totally unbecoming for a democratic party, respectful of British traditions.

The Liberal Democrat motivations are much clearer cut: they’ve lost nearly all their MPs and still want to matter. Some, such as Dr Mark Pack, also seem to hope that if Lib Dem peers start acting like senators, a senate will be the result.

The Conservative Party thus finds itself confronting two challenges. As the elected Government, it has a duty to enact its programme. As the truest defender of the British constitution, it must find a way to bring Opposition peers into line without vandalising it.

A tidal wave of Tory peers is not a long term solution, although it would address the immediate challenge the Government faces in enacting legislation. We are early enough in the Parliament that decisive and determined application of the Parliament Act will (eventually) see the will of the Commons done.

There will be the inevitable calls from the usual quarters to use this crisis as an excuse to enact the common run of bad ideas: an elected senate, or a codified constitution, for example.

Another notion – advanced by Ridley – is to have the partisan peers whittled down to a ratio which reflects the balance of the parties in the country or the Commons.

My instinct is that this is to be resisted: the Lords is not a democratic chamber, and steps in that direction will only strengthen calls to make it so and thus undermine its function. But some means of balancing the exponential growth of the Lords does need to be found.

Happily, our uncodified constitution allows the Government a lot of flexibility in enacting carefully-targeted constitutional reform.

Thus if Opposition peers are no longer willing to respect the conventions essential to the proper functioning of the upper house, the Government should set those conventions in law.

A temporary tranche of Conservative peers – perhaps with sunset clauses built into their nominations, to expire upon the bill receiving royal assent – could be appointed in extremis to reinforce the Government’s position on the red benches until such reforms were enacted.

This would be a legitimate and genuinely Conservative approach, which would be at once a reform and a form of restoration of the proper workings of Parliament, and do so by exploiting the organic flexibility of our constitution to minimise unnecessary disruption and change.

Desperate opposition parties, divided in or almost vanished from the Commons, are attempting to break the constitution in order to thwart the Government. As Conservatives, it’s our job to make sure they don’t succeed in either aim.