"The campaign is over and the work begins," - declared Boris Johnson, promising to energise the country.
How will he energise the economy, which has fallen from the top to the bottom of the league of G7 leading economies since the Brexit vote?
UK's Office for Budget Responsibility warned that a no-deal Brexit would push unemployment above 5% , send house prices tumbling by around 10% and finally would plunge Britain into a recession that would shrink the economy by 2% next year.
The National Institute of Economic and Social Research says the economy may already be in recession.
Several business groups have rushed to release their advice for the new PM - to bring certainty and, ideally, an orderly Brexit.
Rating agency Moody's has warned that Boris Johnson's win increases the risk of a no-deal Brexit.
The International Monetary Fund released its latest economic outlook. It now expects the UK's economy to expand by 1.3 % in 2019. But this forecast assumes an orderly Brexit followed by a gradual transition.