LONDON – Boris Johnson is barely a week British Prime Minister and the honeymoon seems to be over. His conservative party lost a special election and brought back its working majority in parliament to only one seat at a critical moment for the country.
The narrow defeat in a previously conservative district, the Brecon and Radnorshire area of Wales, was a brutal reminder of Mr. Johnson’s weakness in parliament.
It immediately fueled speculation that Mr. Johnson would try to increase his majority by holding more general elections. The only question is whether it is before or after October 31 the deadline for the country to leave the European Union.
“The election campaign has actually begun,” says Anand Menon, professor of European politics and foreign affairs at King’s College London.
The results from Wales made it clear that an election is needed. But they also suggested that Mr. Johnson cannot be certain of the victory if someone took place in the fall. And that is the dilemma for Mr. Johnson.
Johnson has long been the cheerleader for pro-Brexit troops, and since he became prime minister, he has doubled his promise to leave the European Union on time, with or without a deal that regulates future relations with the bloc.
Parliament has three times rejected the Brexit deal pushed by Mr Johnson’s predecessor, and most legislators oppose a no-deal Brexit. With European officials determined that the withdrawal agreement cannot be reopened, Johnson is preparing for a showdown on his plans.
Even with the support of 10 legislators from Northern Ireland, a working majority of only one seat makes the new prime minister particularly vulnerable.
The defeat in Wales has also illustrated how Brexit is redefining British politics, exceeding traditional party lines with unpredictable consequences if voters focus on the tortured Brexit efforts.
Officials announced early Friday that Jane Dodds, the candidate for anti-Brexit Liberal Democrats, had defeated the conservative established leader, Chris Davies, with 1,425 votes.
Mrs. Dodds was helped by an experimental “stay alliance”: two small parties did not contest the seat not to split the anti-Brexit vote. She won although a majority of voters in the region voted for the Brexit in the 2016 referendum.
Mr. Johnson’s energy and cheerfulness, if it is blurry, has rhetorically welcomed the conservative supporters and gave his party a bounce in some opinion polls, one that was reflected in the nearer-expected outcome in Brecon and Radnorshire.
Normally, conservatives expect to keep the seat after winning it comfortably in 2017 with around 8,000 votes.
But the circumstances that led to the elections made the conservatives more complicated. Their elected candidate, Mr. Davies, was not present by a petition from local voters after he was convicted of filing a claim for false expenses. The party chose him to fight for the chair.
But the results also showed increasing challenges for all major traditional regular parties. The main opposition party, which is ambiguous about the Brexit, was pushed to a shameful fourth place, the vote of which was pushed by the anti-Brexit alliance.
Nigel Farage’s populist Brexit party came in third with about 10 percent of the vote, enough to suggest that it remains a problem for Mr. Johnson despite his efforts to neutralize it by filling his new cabinet with hardliners.
During a tour of the UK this week, Mr. doubled Johnson also has red lines for negotiations with Brussels, raging anger in Scotland and Northern Ireland that voted to stay, and rattling investors who sold the pound.
If he kept his word, he or the European Union would change course.
If that fails, Mr. Johnson’s determination to leave the bloc would nevertheless face a revolt in Parliament, where a majority of legislators oppose a potentially chaotic “no deal” Brexit.
However, it is unclear whether lawmakers can find a legally watertight way on October 31 to prevent Britain from crashing out of the European Union.
Conducting an election after such an outcome could help Mr. Johnson to brag supporters of the Brexit party after they have achieved their mandatory goal.
But it can entail the serious risk of fighting an election against the backdrop of chaos.
The reactions of British consumers to possible food and drug shortages are impossible to predict, as well as the broader economic, political and constitutional consequences of a sudden breach.
“Keeping an election after” no deal “risks the ability and willingness of the British people to stay calm and continue to exaggerate,” said Mr. Menon, the political professor.
“We are not responding well to a crisis,” he added, pointing to the response to a gasoline shortage in 2000 and to the shock of Britain’s forced exit in 1992 from an exchange rate system linking European currencies.
When Britain held general elections during a crisis in 1974, the prime minister lost. Voters may have become less tolerant to disruption since then: last year, when the KFC chain ran out of chicken, some angry customers contacted the police.
Johnson could face voters before Brexit is complete, and demand a mandate from them to continue while blaming Parliament and the European Union for obstructing him.
“I think in his ideal world he would like definitive proof that Parliament is trying to obstruct Brexit,” said Menon, “and that the European Union is blocking him and that he has no alternative.”
In terms of the timing of the elections, Mr. Menon said, “October looks increasingly likely.”