In 2011, the Conservative-Liberal Democrat coalition government laid out its detailed methodology for the Boundary Review. Its central claim was that “the principle of greater equality” would be at its heart. Eight years on, the review that resulted couldn’t be farther from that promise. Dubbed a “power grab” by Labour, it is widely thought to be unlikely to command a majority in the Commons.

This led to a report one year ago by the Commons’ Public Administration and Constitutional Affairs Committee, calling for an urgent parliamentary debate to bring about a new review. Continuing with the existing boundaries, it warned, “is not a step that should be taken lightly,” given that they are based on data that is more than two decades old.

As an insight into how bad the existing boundaries are, the MP for West Ham, Lyn Brown, currently represents a constituency population of 174,534 – 105,000 more people than the MP for Wirral West, Esther McVey. This makes sense neither in terms of equal democratic representation, nor of equal access to representatives by constituents, nor equal workload for MPs.

Last month, the committee stage of Afzal Khan’s Private Member’s bill to moderate the existing Boundary Review and its damage to our democracy had its twenty-seventh weekly meeting. It adjourned after a few minutes – as did the other twenty-six, stuck in Groundhog Day because the government refuses a money resolution to allow the committee to proceed. To conceal the likelihood of parliamentary defeat, the Boundary Review itself awaits a ‘complex and lengthy statutory instrument’ which will take months to prepare – if it is ever prepared.

My study of the impact of the Review, Challenging the Democratic Deficit, avoids mentioning political party advantage. Instead, it focuses on exposing the ways the Boundary Review as it stands would deepen geographical inequities favouring the better-off. It finds that the Review’s relationship with its founding commitment to greater equality is tenuous, at best.

Looking in detail at the proposals, analysis for my report found that the ten proposed new constituencies with the smallest adult populations in England and Wales will have on average 43,720 fewer resident adults than the ten with the largest adult populations. So some parts of the country will continue to get considerably more MPs to the pound for their vote than others. And, unsurprisingly, those areas underrepresented are far more likely to be deprived.

In Liverpool Riverside, a third of the adults eligible to vote are not registered. They were excluded from the Review. Analysis suggests that in the ten constituencies with the lowest level of registration, nearly a quarter of a million eligible but unregistered voters were excluded from the process. It is hard not to conclude that if it goes through, the Boundary Review will entrench the United Kingdom’s historic resistance to the principle of univeral suffrage.

So how did we get to this point? The Boundary Review was tasked with using the population of registered electors to redesign constituency boundaries. It assumed the exclusion of millions of adults who are eligible to vote but not registered, resulting in a proposed map of new constituencies which are as wildly variable in population as the current system. Its inflexibility has led to new flaws, including more splitting of constituencies across local authority and even electoral ward boundaries. This will cause disruption in local government, confusion over democratic accountability, duplication, and waste, as the Government was warned in great detail from early on.

Electoral registers have been particularly volatile in recent years. In 2016 and 2017 more than four million new voters were registered, but they were not counted in drawing the new boundaries because of a cut-off point in December 2015, enforced against the advice of the independent Electoral Commission. The excluded populations contained a high proportion of young people, private tenants and people from ethnic minorities.

There is a simple and sustainable remedy which can bring about equity and transparency in the distribution of parliamentary seats. The Review depends on a legal definition of ‘electorate’ which is limited to those registered to vote. If that were changed to the total number of persons eligible to vote by dint of age and citizenship, it would represent the true electorate – applying the principle of universal suffrage to constituency boundaries for the first time ever. This would truly meet the government’s commitment to a “principle of greater equality in the value of each vote.”

The small area statistics we would need to carry out such a review have already been produced by the Office for National Statistics and National Records of Scotland. Subtracting foreign nationals who are not eligible to vote is a tricky part of this, but can be done: initially derived from the census, it can be adjusted using the Annual Population Survey data on nationality. The method is not perfect, but it is a good deal more robust and sustainable than using voter registration.

This is only the start of a much broader change in approach that is needed. Future boundary reviews should be timed at two or three years after each ten-yearly census, and must come with a commitment to maintain and improve the data. 16 and 17-year-olds should be added to the population used, so that any new Review would have a longer shelf-life as well as preparing the ground for votes at 16.

The practice of defining our parliamentary boundaries through a structural obstacle to universal suffrage is not democratically legitimate, regardless of how long it has endured as an approach. The contrasts in population size in the proposed constituencies identified in my report, as well as the analysis of current constituencies with the lowest levels of registration, point to a conclusion that the lack of a level playing field in the last election undermined the integrity of the result.

Future waves of registration will result in younger voting populations corralled into fewer constituencies with fewer MPs, further distorting election results. The results of this inequity are not distributed equally – as we know, the majority of people aged under 48 voted Labour in the 2017 election.

If the Boundary Review is not approved and there is nothing to replace it, the 2022 general election will be fought on boundaries that were already in place – and already questionable – at the beginning of this century. But there is still an opportunity to structure our democracy rationally in a way consistent with the principle of universal suffrage: by tagging the change of definition onto Afzal Khan’s bill.

At the moment, this bill is limited to reversing the proposed reduction in the number of MPs, and slightly loosening the Boundary Review’s narrow and rigid parameters for constituency size. While those reforms are welcome, they are still built on a fast-shifting and selective foundation which builds in obsolescence.

There is a compelling case for incorporating Afzal Khan’s reforms with a radical, sustainable and historic democratic reform – and for this to find a place in Labour’s next manifesto. There’s a faultline in our democracy that has long been hidden in plain view, and the more justifiably disillusioned the electorate, the harder it is to hide. To shape our constituencies on an equitable basis, we need a definition of the electorate which does not shut out millions who are eligible to vote. Our democracy deserves that.