The 2016 Richmond Park by-election must surely be one of the most frivolous and pointless instances of political suicide in recent British political history.

Conservative incumbent Zac Goldsmith should perhaps be praised for sticking to his promise of resigning if the government backed a third runway for Heathrow airport to stand as an independent candidate. But he could clearly have done far more to support his cause had he not made that promise.

It can only be hoped that his defeat by Liberal Democrat Sarah Olney will put an end to the expensive and self-indulgent trend of MPs stepping down, only to then run in the subsequent by-election.

While Richmond is traditionally a Conservative area, the party’s lead has often been relatively modest (and non-existent for a while after 1997) in the current constituency and its predecessors. Goldsmith won by a significant margin – a majority of 23,000 – in the 2015 election, but that was unusual and linked to the general Lib Dem collapse that year.

Nevertheless, the Liberal Democrat victory in this by-election is a serious upset, for Goldsmith himself obviously, but also for the government. With one fewer Conservative MP, its already narrow majority has been cut further. The idea that Goldsmith was an independent candidate was always somewhat fictitious considering the lack of an official Conservative candidate. This is very much a defeat for the Conservatives, regardless of Goldsmith’s formal non-affiliation. The bottom line is that a Conservative-held seat has gone to the opposition.

‘Zacxit’

Ironically, the decision by the Conservative Party to not run a candidate may actually have harmed Goldsmith’s main appeal – his opposition to Heathrow.

Regardless of their personal views on the issue, any Conservative candidate would inevitably have been seen as the Heathrow candidate due to the government’s decision to support the third runway. The absence of a Heathrow candidate (all the other significant candidates opposed the runway plans) meant that the Lib Dems’ tactic of turning the by-election into a referendum on what kind of Brexit the country wanted, rather than a referendum on Heathrow, had a far easier time than it otherwise would. Obviously, a Conservative candidate would have split Goldsmith’s vote, but at least he would have had a more solid target for his anti-Heathrow position.

For Goldsmith himself this is almost certainly the humiliating end of an otherwise promising political career. High office was perhaps unlikely to be in the offering but he was a diligent and hardworking local MP. However, his campaign for London Mayor was deeply divisive and unpopular, even with his own party. Having now thrown away a Conservative-held seat for his own personal gratification he is unlikely to find another local Conservative association to make him their candidate.

In wider terms, this result suggests that an anti-Brexit campaign can still succeed despite evidence that Remainers have, to a large extent, accepted that leaving the EU will happen. It does seem that concerns over the specific terms of the departure can be leveraged for electoral gain.

This will no doubt be used by Remain campaigners to argue that there is support for soft Brexit. However, one should not read too much into the result in a Brexit context. It does appear that the Lib Dems’ anti-leave, or at least soft Brexit position resonated, but Richmond Park was also one of the most staunchly Remain constituencies in the country. A similar approach is unlikely to have much success in areas where Leave support is lower. This campaign mobilised existing Remain support. It is unlikely to have changed the minds of any Leave voters.

What happened to a progressive alliance?

Much has been said of a so-called “progressive alliance” of opposition parties working together to take on the government. And indeed, this victory could be seen as a slightly more positive end to a year that has been pretty disastrous for “progressives”. However, no such alliance was in evidence in Richmond Park.

Labour stuck stubbornly to its Clause I objective to “support, and promote the election of Labour Party representatives at all levels”, regardless of how unlikely victory might be. The local Green Party did agree not to run anyone in the by-election but, at the same time, refused to endorse Olney.

Clearly, for a progressive alliance to have hope of success, progressive parties need to be willing to give others a clear run, and be politically mature enough to support the progressive candidate most likely to win, regardless of how weak one might believe their progressive credentials are.

At the very least, had the Labour Party had the sense to have gone with the “progressive alliance” line in a constituency where it had no chance of ever winning, it could have avoided the humiliation of that traditional symptom of a party in trouble: the lost deposit.

Robin Pettitt is a member of the Loughton Residence Association and the Women's Equality Party.

This article was originally published on The Conversation. Read the original article.