Labour wins in the U.K.’s two biggest cities completed a string of local election successes by opposition leader Keir Starmer that showed his party firmly on course for victory at a general election later this year.

Not only did Sadiq Khan comfortably win a historic third term as London mayor, but Labour candidate Richard Parker eked out an upset over the Conservative incumbent in the West Midlands, which includes Birmingham. The results announced Saturday dashed any hopes Prime Minister Rishi Sunak had for more positive performances to reassure Tories anxious the party could get wiped out in a general election expected later this year.

The defeat of West Midlands Mayor Andy Street, who had clashed with Sunak over the prime minister’s decision in October to cancel a high-speed rail line from Birmingham to Manchester, was a particular blow. Sunak’s allies had cast a Street victory as evidence that a popular incumbent could withstand a red wave of Labour support. He lost by just over 1,500 votes after a recount.