BlackRock’s influential research and analysis unit has said severe political upheaval in the UK over the past week has reduced the likelihood that the country will leave the European Union with a deal in place — indicating a more extreme outcome is now more likely.

The prediction from the world’s largest asset manager comes as the UK parliament begins a five-week shutdown — or prorogation — after prime minister Boris Johnson failed for a second time to win the support of MPs for his plan to hold a general election in October.