CNN  — 

Britain’s pro-European Liberal Democrats have beaten the governing Conservatives in a special by-election, striking a major blow to Prime Minister Boris Johnson and reducing his already narrow working majority in Parliament to just one.

Liberal Democrat candidate Jane Dodds won in the Brecon and Radnorshire region of Wales, defeating Conservative candidate Chris Davies, who had previously held the seat.

The Conservative loss follows Johnson’s pledge to take Britain out of the European Union by October 31 without a deal if necessary, and will likely be seized on by pro-European lawmakers as apparent proof that voters do not back his hardline stance.

“The people of this constituency have once again chosen hope over fear,” Dodds said in a speech after the results were announced, calling the victory “a powerful message to Westminster.”

“My very first act as your MP (member of Parliament) when I arrive in Westminster will be to find Mr. Boris Johnson, wherever he’s hiding, and tell him loud and clear, ‘Stop playing with the future of our communities and rule out a no-deal Brexit now.’”

The Liberal Democrats’ official Twitter page congratulated Dodds, calling her victory a “fantastic result.”

Dodds won with 13,826 votes, with Davies trailing by 1,425 votes. The opposition Labour Party also took a hit with only 1,680 votes – a mere 5.3% of voters.

The by-election took place after Davies, the previous lawmaker, was convicted of a false expenses claim. More than 10,000 residents signed a recall petition, ousting him from the seat.

Davies’ failed attempt at re-election has reduced the pro-Brexit Conservative Party’s working majority in the House of Commons to one, meaning Johnson will have to rely on the support of his own lawmakers as well as partners in the Democratic Unionist Party (DUP) to pass legislation during crucial Brexit votes.

Parliament has previously voted to reject leaving the EU without an agreement. Lawmakers are preparing to again block the possibility, with many fearing a so-called no-deal Brexit will result in major economic disruption.

Johnson inherited a deeply divided Parliament. The Liberal Democrats’ pro-EU stance is a striking contrast to Johnson’s readiness to break out of the bloc without any deal in place.

When he entered office in July, Johnson pledged to do in three months what previous leader Theresa May could not do in three years – lead Britain out of the EU, “do or die.”

Official forecasts suggest that this kind of hard Brexit risks triggering a recession and the British pound taking a nosedive – but Johnson warned that the UK must prepare for such a scenario.

If he cannot negotiate a new deal with the EU, Johnson may try to force Brexit through on Halloween. He has so far refused to rule out suspending parliament in order to do so.