Since I came into the House of Lords three years ago, I have been infuriated by one particular mantra: “We’re the unelected House, so we can’t stop the government doing X.”

That “X” might be some deliberately weak, half-baked or ill-thought-through action by the government – I can’t count the number of those measures. But it also could be, say, something that breaks international rules, or is so clearly abusive of human rights or the rule of law as to be indefensible.

This mantra is what I heard when I called a vote in January to throw out part 4 of the last Policing Bill, which deliberately targets gypsy, Roma and traveller people. (We lost, but credit to the Liberal Democrats who backed me wholesale, and the nine Labour rebels who broke the abstention whip.) It is what I heard this spring, when the Lords finally dropped their opposition to the government plan to ship asylum-seekers to Rwanda.

There have been two occasions in my time when the Lords threw off their “unelected” shackles and properly challenged the government – over the Internal Markets Bill and the record 14 defeats for the government on the Policing Bill – but hearing that “unelected House” saying makes me even more convinced that we need an elected upper House instead.

An elected chamber would remove that excuse for inaction, for failing to stand up for the rule of law and human rights, or even against stupidity and bad law. And that’s not to mention the use of patronage to create life peers, or the 92 remaining hereditary peers.

So I was delighted to see the headlines indicating that Keir Starmer would be backing Gordon Brown’s plans for an elected upper chamber. (Great to see once again that, where Greens lead, others follow – we have long proposed an upper chamber elected by proportional representation.)

But when you dig into what Labour is actually saying, the foundations for those headlines are less than solid. All its Commission for the Future report says about the composition of the chamber is that it “must have electoral legitimacy… with the precise composition and method of election [to be] matters for consultation”.

That leaves open a great many possibilities. Would elected mayors, with their own highly centralised structures, and undemocratic first-past-the-post elections, make up this upper chamber, for instance? It would be great to hear someone ask Sir Keir if he’ll rule out that idea.

The report doesn’t say “democratically elected”, and it certainly does not say “proportionally elected”. Nor does it say what would happen if the electoral system for the House of Commons is left unreformed – Starmer has already said he plans to ignore the vote at this year’s Labour Party conference to make proportional representation a manifesto commitment.

That leaves the report fundamentally flawed. It says that the new chamber’s power would be restricted so that it could not overrule the Commons. But what would happen if a proportionally-elected upper chamber – where the number of seats actually matched the number of votes cast for each party – rejected a dreadful, unpassable bill presented to it by the first-past-the-post House of Commons? What if it is another Internal Market Bill or, say, a Liz Truss financial statement? As an Australian, I’m all too familiar with this form of constitutional crisis.

I often discuss making the UK a democracy – since its archaic, dysfunctional, unwritten constitution means it isn’t currently – with the campaign organisation Make Votes Matter. The group is wary that Lords reform could distract from the more important goal of making the House of Commons properly reflect the will of the people. Full proportional representation would end the situation where a Boris Johnson – or anyone – can get 100% of the power with the support of 44% of people who voted. An elected House of Lords would inevitably demand House of Commons reform.

Finally, it is worth a short reflection on other parts of the report, for Lords reform is only a small part of it. Its focus on the need to devolve power and resources from Westminster down to local communities is welcome.

But I entirely disagree with the report’s focus on “growth” as the way out of our current extreme malaise. The word “resilience” appears only once. “Growth” appears 108 times. “Fairness” appears eight times, mostly in the context of regional inequality. Financial “redistribution” is referred to just once.

We cannot have infinite growth on a finite planet. There are enough resources on this planet for everyone to live well, and for climate and nature to be restored, but only if we transform our economic system and share those resources out fairly.

On those fundamental issues, Labour still has nothing substantive to say – just as it has nothing coherent to say on the fundamental changes needed in Westminster to make the UK a democracy.