(Bloomberg) -- The mayor of London added his voice to the growing calls for another referendum on Britain’s membership in the European Union, heaping more pressure on Labour leader Jeremy Corbyn to come off the fence ahead of his party’s annual conference next week.

Writing in the Observer newspaper, Sadiq Khan, a Labour member, said hadn’t thought he would back another national vote on Brexit. The Conservative government’s handling of negotiations has been so poor, he said, that now he can’t see any alternative to giving Britons another chance to stay in the EU. He said there are only two options left -- a bad deal for the U.K. or, worse, no deal.

“This means a public vote on any Brexit deal obtained by the government, or a vote on a ‘no-deal’ Brexit if one is not secured, alongside the option of staying in the EU,” he wrote.

So far, Corbyn and his shadow chancellor John McDonnell have said they would prefer the public be given a say on Brexit in a fresh general election, although the option of pushing for a second referendum should be left open.

Today, McDonnell joined protesters outside the Bank of England marking a decade since the collapse of Lehman Brothers and the onset of the global financial crisis. He reiterated his party’s call for a financial transaction tax on derivatives that would raise as much as 5 billion pounds ($6.5 billion) to pay for schooling and child care.

Brexit remains virtually the only topic on the U.K. government agenda. EU leaders will discuss the latest U.K. proposals at an informal meeting in Salzburg, Austria, on Wednesday. Former Foreign Minister Boris Johnson used a newspaper column yesterday to urge his fellow Brexiteers to shoot down Prime Minister Theresa May’s plan rather than try to oust her altogether.

To contact the reporter on this story: James Ludden in London at jludden@bloomberg.net

To contact the editors responsible for this story: Sarah Gill at sgill23@bloomberg.net, Bernard Kohn, Bob Brennan

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