The U.K.’s ruling Labour Party should commit to rejoining the EU at the next general election, London mayor Sadiq Khan has told CNBC.

In an interview on Monday, Khan acknowledged his party’s disastrous showing in local elections last week. He urged the government to be “bolder and braver,” and deliver on its promises, as party lawmakers openly discuss replacing Prime Minister Keir Starmer.

“People are frustrated with the lack of pace of delivery,” Khan told CNBC’s Ritika Gupta.

“We have not been bold enough, we’ve not been brave enough. We are in danger of losing the next general election pretty badly.”

Khan welcomed a speech by Starmer after the election results, in which the prime minister indicated that the U.K. government would rebuild ties with the European Union, including strengthening its alignment with the bloc’s single market and customs union.