Around about now, had David Cameron and George Osborne not been saved from themselves, a lot of people were going to have a Fright Christmas. An unfestive greeting from Downing Street was scheduled to thump through the letter boxes of millions of voters with the miserable tidings that the government was about to make them very much worse off because of cuts to tax credits.

If that had occurred, this would also be happening. Agitated Tory MPs would be all over the airwaves howling to interviewers that their constituency surgeries were filling up with distressed and angry voters. The news bulletins would be leading with the stories of the cuts’ distraught victims, some tearfully telling reporters that they had been forced to tell their children that Santa Claus would not be visiting them this year. Opinionators of left, right and centre would be belabouring the prime minister for perpetrating a dreadful political blunder while predicting that the chancellor had ruined his chances of getting to Number 10. The cartoons would have been vicious. The least of it would have been portrayals of George Osborne as an unredeemed Scrooge. Even the Labour party might have taken a break from its existential crisis to exploit the avalanche of protest that would be crashing down on the government’s head.

There is a reason Fright Christmas did not happen. It is called the House of Lords. When peers were asked to sanctify the tax credit cuts, you will recall that the second chamber told the government to go away and have another think. After much hollow bluster, the government did have another think and concluded that the second chamber was right. In his financial statement last month, the chancellor suddenly found a stash of money down the back of the Treasury’s sofas and announced that he was abandoning the cuts to tax credits. He gave himself a slap on the back for being wise enough to listen to the representations against his own policy. Relieved Tory MPs cheered him to the echo. The rebellious peers had done everyone a great favour. They saved millions of low earners from a bleak midwinter, they saved the government from a bad decision and they saved George Osborne from making a potentially career-wrecking mistake.

By way of thanks, the very least he might do is send a bottle of champagne to each of the peers who gave him the chance to think again. Yet instead of expressing gratitude, he and the prime minister are bent on exacting their revenge against the upper chamber. The government announcements rushed out on the last day before parliament’s Christmas break included the publication of a “review” of the powers of the second chamber by Lord Strathclyde, a former Tory leader of the upper house and a hereditary peer. Tom Strathclyde is a jovial cove with a good sense of humour. So I am sure he will not mind if we all have a belly laugh at the wonderful risibility of a man who inherited his seat in parliament opining on the legitimate role of the second chamber in a democracy. His conclusion? Since this “review” was commissioned by the prime minister in a fit of pique with the peers, it is no surprise to find that Lord Strathclyde effectively recommends that the Lords be denuded of their ability to challenge secondary legislation – precisely the mechanism used in the case of tax credits.

Facebook Twitter Pinterest Lord Strathclyde, charged with a review of Lords reform. Photograph: Martin Argles/The Guardian

The Lords is decades overdue for reform. This weird amalgam of appointees and hereditaries is the world’s most bizarre legislature. Distinguished worthies and alpha minds in their fields of expertise sit with retired MPs, prime ministerial cronies and party donors. I was going to say that the ermine-clad chamber is wholly unrepresentative of society, but that would not be entirely just. For it does contain a reasonable proportion of crooks. The upper house has become absurdly bloated as successive tenants of Number 10 have packed the red benches with their supporters. The Lords is now the second largest legislative assembly on the planet after the National People’s Congress of China. That body at least makes a show of being democratic. The Lords can’t even pretend to be that.

That is the real scandal about the second chamber of our parliament and it is one David Cameron has no interest in addressing. He went along with an attempt to reform the Lords during the coalition because the Lib Dems insisted upon it, but he didn’t fight all that hard to prevent it from being sabotaged by Tory MPs and peers. His election manifesto dismissed Lords reform as “not a priority”.

Far from being “too big for its boots”, as the government would have it, the fundamental problem with the Lords is that it is not a terribly effective check on executives when they do wild, silly or sinister things. Peers have no power over anything budgetary. They were only able to act over tax credits because the government tried to be sneaky and slip the cut through as a statutory instrument rather than primary legislation. Peers do not challenge policy for which a government has a mandate from its election manifesto. And if there is ever a serious confrontation between the two chambers, the government can always wield the sledgehammer of the 1949 Parliament Act that compels the Lords to bow to the will of the Commons.

In practice, it is rarely used because the Lords lacks democratic legitimacy, peers know it, and so they usually back down when faced with a government determined to have its own way. Peers have a veto over nothing. All they have is a brake. By obliging ministers to pause, the Lords can stiffen the spine of the Commons and make governments reconsider a policy, which is what happened over tax credits. That is the modest restraint on the executive the Strathclyde gambit would undermine. The government’s reasons for doing so are nakedly partisan. During the many decades when the Tories enjoyed a built-in majority in the Lords, they were entirely comfortable with the powers of peers, especially when they were used to frustrate Labour governments. During the Blair and Brown years, the second chamber inflicted more than 500 defeats on ministers. I am struggling to remember David Cameron and George Osborne calling that a constitutional outrage. It is only because we are in the novel situation of having a Conservative government without a majority in the Lords that they have decided that peers have become too uppity.

Our unwritten constitution imposes only feeble curbs on the executive as it is. An American president would kill for the powers enjoyed by a British prime minister in possession of a Commons majority. It would be bad enough if the attack on the peers were just an example of a government messing with the rules in a hissy fit. More disturbing is that it fits with a trend of moves all designed to advantage the government at the expense of accountability, scrutiny and the opposition.

Shortly after the election, I first alerted you to how the Conservatives planned to reshape the electoral landscape to their benefit. There is the direct attack on Labour’s funding base from the trade unions that is now to be accompanied by an assault on the financing of all the opposition parties by depriving them of a substantial slice of the “Short money” that supports their activities in parliament. The redrawing of constituency boundaries will be worth a sackful of extra seats to the Tories at the next election. At the same time, the introduction of individual electoral registration will very likely reduce the number of non-Tories on the electoral roll while an extension of the franchise to longstanding expats will very likely boost the numbers of Conservative voters.

In each individual case, you can muster an argument for why the change is not unreasonable. Individual voter registration is supposed to make it harder to commit electoral fraud. Constituency boundaries are overdue for a review. Party funding needs an overhaul. It is the cumulative effect that reveals their strategic intent. As does the blatant bias of “reforming” Labour funding without addressing any of the issues about the way the Tories are bankrolled by hedge funds and corporates. Each change favours the Conservatives or makes it harder to hold the executive to account.

The “review” of the operation of Freedom of Information Act is yet another example. No one thinks that has been set up to conclude that there should be more transparency in Whitehall decision-making. Absent a written constitution, the ancient tapestry of our democracy is woven from precedents, conventions and understandings. The most important of those is that the government does not exploit its power to grossly advantage itself over the opposition, if only for fear of what might happen when their positions are reversed.

The Tory lord chancellor Lord Hailsham observed that the possession of a Commons majority allows a British government to aim to be “an elective dictatorship”. It is one of the hallmarks of dictatorship that it is unable to see that government needs checks and balances on its behaviour, both to protect us from an overbearing executive and to save our rulers from themselves.