LONDON — If Brexit were a JRR Tolkien fantasy, we are right now in that stage in the story where the heroes are forced to retreat or get captured in a cave of some sort — one more digression, one more roadblock on the way to destroying the ring. Or, in this case, liberating Britain from the European Union.

On Monday, British members of Parliament were denied the chance, yet again, to vote on the new exit deal Prime Minister Boris Johnson clinched from Brussels’ jaws.

The debate on the bill, scheduled to commence Tuesday, is now subject to a more complex, lengthy timetable, further risking Britain’s opportunity to leave the EU by the end of the month. The loser in all this is democracy itself.

Poll after poll shows that Britons are sick of more delays. They are tired of politicians endlessly debating Brexit. Much like the 2016 election in the United States, Brexit has torn family and friends asunder, and there is a strong desire for tensions to ease.

But Brexit has also become a matter of trust between the public and the Parliament that represents it. If the outcome of the 2016 referendum, in which a clear majority voted for Brexit, isn’t respected, faith in future votes will be jeopardized.

The failure to deliver Brexit can largely be blamed on the dithering of many British members of Parliament, who are using every underhanded trick to stop the process. In truth, plenty of them don’t want ­Brexit to happen at all. They imagined they would never have to cast a vote, assuming a reworked deal would never land on their desks.

Defying great odds, however, Johnson brought home at the 11th hour a deal that grants Britain full trade and regulatory ­independence. The deal also addresses Northern Ireland’s delicate situation with a bespoke arrangement, giving the country the power to determine its own future arrangements with the European Union.

MPs met on Saturday — the first time parliamentarians had gathered on a weekend since the Falklands War. They had the opportunity to make history, by voting to deliver Brexit for the British people.

Yet through a series of complex machinations, the Brexit naysayers forced the prime minister to ask Brussels for yet another extension — the third since the referendum — in a clear attempt to thwart Britain’s exit once more.

These MPs threaten not only the public’s faith in democracy, but also the big opportunities created by Brexit, including Britain’s ability to venture out globally and secure its own free-trade deals with other countries, freed from the Brussels mandarins’ yoke.

There has already been a great deal of interest from other, non-European countries to trade more freely with Britain. That interest has resulted in more than a dozen “trade-continuity agreements,” covering more than 45 countries, which can come into effect once Britain exits.

And the big prize, a US-UK free-trade deal, presents a huge opportunity on both sides of the Atlantic to boost growth and slash prices for consumers.

America is Britain’s largest export market as a single country, and relationships are only improving. Exports from Britain to the United States already amount to nearly half of those to the European Union, having grown 33% over the last four years, compared with a 22% rise in UK exports to the EU. Then, too, Britain is already the single largest investor in the US economy, and vice versa.

Who stands to win? Consumers in both countries: Britons buying California wine, for example, and Americans buying British fashion. Plus, the growth potential in financial services and technology industries should excite established business and entrepreneurs alike. Right now, the bureaucrats and vested interests are holding all this hostage.

The Brexit saga has already been subject to many false endings, and this week may prove no different. But if a Brexit deal is voted through, it will be a resounding win for democracy. The British people can’t wait to get Brexit over the line, but there’s plenty of reason for those watching from across the Atlantic to cheer its success, too. Here’s hoping this story finds a happy ending.

Kate Andrews is associate director at the Institute of Economic Affairs, a free-market think tank in London. Twitter: @KateAndrs