London mayor Sadiq Khan has called for another referendum on Britain’s European Union membership, saying the prime minister’s handling of Brexit negotiations had become “mired in confusion and deadlock” and was leading the country down a damaging path, Reuters reports.

Britain is due to leave the EU on March 29. But with Prime Minister Theresa May’s Brexit plans still not accepted, some lawmakers, as well as union and business leaders, are arguing for people to have a final say on any deal with Brussels.

May has repeatedly ruled out a second referendum. She says members of parliament will get to vote on whether to accept any final deal.

The backing of Khan, a member of the main opposition Labour party, for a second referendum will put more pressure on Labour leader Jeremy Corbyn to change his opposition to the idea when the party meets for its annual conference in a week’s time.

A second referendum, dubbed a “people’s vote” by its proponents, is not Labour party policy, although finance spokesman John McDonnell said last month that no option should be off the table.

London backed remaining in the EU in the June 2016 referendum that went in favor of leaving.

Khan said Britain was now facing either a bad deal or a no-deal Brexit, both of which were “incredibly risky”.

Writing in Sunday’s Observer newspaper, he blamed the government’s handling of the negotiations and said the threat to living standards, the economy and jobs was too great for voters not to have a say.

“The government’s abject failure – and the huge risk we face of a bad deal or a no-deal Brexit – means that giving people a fresh say is now the right – and only – approach left for our country,” he said.