SOME people say by-elections are boring, but those people are wrong. The result from the Brecon by-election yesterday was a fascinating insight into our changing politics and an indicator of what is to come.

The seat was previously held by Conservative MP Chris Davies before a recall petition over his conviction for submitting fake expenses documents forced an election. With the Greens and Plaid Cymru agreeing not to stand candidates for fear of splitting the Remain vote, the LibDems were victorious on the night.

Labour – achieving only 5.3% of the vote – were humiliated and in losing the seat, Boris Johnson now has a Parliamentary working majority of just one.

Those reporting on the ground say that while local issues were discussed, Brexit dominated the by-election. With tactical voting now common-place, alliances between parties proving effective and voters willing to abandon the two main parties over Brexit – the Tories and Labour should be very, very worried.

This is the bug burrowing its way through the two-party dominance in UK politics. Supporters of the First Past The Post system argue that it produces strong and – dare I say it – stable governments. Brexit has disrupted that accepted wisdom. With Labour and the Conservatives judged on their Brexit stances and facing dissatisfaction from both sides of the constitutional divide, their influence has diminished.

Our exit from the European Union is very much an unresolved and ongoing issue. Leave voters say this feels like a betrayal. Under a cloud of broken promises, extensions to the date we were due to leave and a parliament that they see as determined to overturn the referendum vote – the Tories are floundering.

Labour have been wounded by their determination to appeal both to the Leave voters in their heartlands and their Remain-supporting membership and PLP.

It is understandable that Labour have dithered on Brexit for so long. To take a clear position would be to alienate a section of the support they need to win a General Election. Unfortunately for the party, their vagueness has had the effect of pleasing nobody and angering everybody. For months Labour representatives have tried valiantly to explain their “latest” position on Brexit and a potential People’s Vote with very little success.

Jeremy Corbyn is many things, but a natural salesperson is not one of them. For all the hype surrounding the Labour leader and the crowds that gather at his rallies – he has been neither convincing nor compelling on the issue that currently defines our politics.

An early General Election looks inevitable. While Boris Johnson may say he is not “planning” an election, he knows he might be forced into one. The composition of the current House of Commons is a mathematical quandary for the new Prime Minister.

He faces worse odds than even Theresa May did. In pledging to scrap the backstop and take us out on October 31 – whatever the circumstances – he has left himself with no room to manoeuvre and no clear path to delivering the promise that now defines his career.

An early General Election would bring with it a multitude of risks for the two main parties.

We could end up with a hodgepodge result of kingmakers, concessions, bungs and bribes.

At least until Brexit is resolved – and perhaps for some time after – two-party dominance in UK politics is over. The LibDems have been grudgingly forgiven by some for the sins of the coalition government, as English Remain voters desperately seek an alternative to the Tories and Labour. While the Remain alliance that helped them ride to victory in the Brecon by-election is unlikely to be replicated in a General Election, the LibDems have cause to be hopeful.

Of course, Scotland has already ripped up the two-party system. The 2015 General Election saw a historic shift away from Labour and their grip on power as voters returned 56 SNP MPs. As Ruth Davidson’s party splinter and her stewardship of the Scottish Tories hits the rocks, she too will be gravely concerned about the prospect of an early General Election.

Johnson has shown he intends to focus his political energies south of the Border. His premiership rests on gamble after gamble, as he tries to deliver Brexit on October 31 with a wafer-thin majority and colleagues who are prepared to bring down his government if he does so.

There has never been a better time to be a smaller party. While Labour and the Tories are dizzy with Brexit, the LibDems, SNP and the Brexit Party are reaping the benefits of having a clear, easily understandable position on Brexit.

While it may be too early to know which of the smaller parties will hold the balance of power at the next General Election, this is undoubtedly their moment. Alongside their election strategy, they will surely be considering what they can extract from the two big beasts of UK politics in return.