London     -   Britain’s Boris Johnson faces his first test at the ballot box Thursday in a by-election that could reduce his parliamentary majority to one, making it harder to enact his Brexit plan. Just over a week after he took office as prime minister, Johnson’s governing Conservative party looks set to lose the Welsh seat of Brecon and Radnorshire to a pro-European candidate. He is already facing strong opposition in the 650-seat parliament to his plan to take Britain out of the European Union without a deal if necessary on October 31.

Victory for the anti-Brexit Liberal Democrats in Brecon would embolden those opposition MPs and some Conservatives who have pledged to do whatever it takes to stop a “no deal” departure.

Finance minister Sajid Javid on Wednesday announced an extra £2.1 billion ($2.6 billion, 2.3 billion euros) to prepare for the possibility of no-deal, with a parliamentary showdown looming when MPs return in September.

The extra cash will be used to launch a public information campaign and “accelerate preparations at the border, support business readiness and ensure the supply of critical medicines,” said a government statement.