Anti-Brexit demonstrators wave flags and placards during a protest opposite the Houses of Parliament, London, Britain, December 4, 2018. REUTERS/Henry Nicholls

(Reuters) - There is now a 40 percent probability of Britain staying in the European Union, economists at JP Morgan said on Wednesday, citing a European Court of Justice opinion the previous day that Britain could unilaterally revoke Brexit if it wanted.

“The UK now appears to have the option of revoking unilaterally and taking a period of time of its own choosing to decide what happens next. That time could be used to hold a second referendum on terms entirely decided by the UK,” Malcolm Barr wrote in a research note on Wednesday.

He raised the probability of no-Brexit to 40 percent from 20 percent previously, and also raised the likelihood of a no-deal “hard” Brexit to 20 percent from 10 percent He lowered the chance of an orderly Brexit to 50 percent from 60 percent.