Pairing is one of parliament’s least understood and most important traditions: as MPs have to be there in person to vote, members of parliament who are sick, on maternity leave, caring for an ill relative, or on ministerial business often miss votes. To avoid changing the outcome through absences, MPs are “paired” with a politician who is going to vote the opposite way, and they stay away from the chamber as well.

But in Tuesday night’s close votes, Brandon Lewis, the Conservative Party chairman, voted despite being “paired” with Jo Swinson, which he put down to an “honest mistake”. That raised eyebrows, as the mistake was conveniently confined to two votes the government risked losing. Now, the Times reports that two further Conservative MPs were asked by party whips to vote, despite being paired with opposition MPs who were absent.

Pairing isn’t codified in law or in Erskine May – the “bible” of parliamentary procedure – but is merely an arrangement between the political parties. The arrangement tends to become more fractious when the government of the day has a small or non-existent parliamentary majority, as the stakes are higher. Although the United Kingdom had a hung parliament from 2010 to 2015, the combined Conservative-Liberal Democrat majority was 77, which meant that defeats (or even the risk of them) were rare in the extreme. During the last genuinely hung parliaments in the 1970s, pairing was more contentious and in 1976 it broke down entirely after the-then Conservative opposition led by Margaret Thatcher believed (wrongly, it turned out) that the Labour government had abused the pairing system to win a key vote.

Back then, the government was eventually cleared following an inquiry. It could be that the same thing happens on this occasion, but it looks unlikely to happen in this case, as the government’s stories are already contradicting one another and one MP has already admitted it was deliberate.

There are several immediate consequences: the first is that it is a self-inflicted wound for the government that could make it harder for it to get its business done. Remember that while MPs of every party can fall ill, it’s only the governing party that has ministers whose work can take them away from the House of Commons. If the opposition parties don’t think that their pairs will be honoured then they will have no reason to extend the benefit. The second consequence is that it has significant repercussions for the personal lives of MPs, who will find it still harder to juggle work and life. Some will put major life decisions on hold to avoid inconveniencing their side, if they worry that they won’t be paired.

The third will be the consequences that ought to happen, but won’t: that for the second time in three weeks, ministers will have misled parliament with no consequence. And those repercussions are the most troubling of all.