Britain’s opposition Labour Party won contests for two new lawmakers on Friday, dealing a crushing blow to Prime Minister Rishi Sunak’s Conservatives before a national election later this year.

The double defeat underlined the flagging fortunes of the governing party and will do little to silence Sunak’s critics, who fear the Conservatives could face an all-but wipe-out at the national election and want him to change course.

The 43-year-old former investment banker has struggled to restore his party’s fortunes despite recasting himself at various points over the past year as a bold reformer, a stable technocrat and now as someone who needs more time “to stick to the plan” because, he says, that plan is working.