Britain has got poorer because of Brexit, former chancellor Philip Hammond has admitted.
The senior Tory said the Covid-19 pandemic and the soaring cost of energy have also contributed to the cost of living crisis.
His comments are significant because the government has repeatedly denied that leaving the European Union has had a negative impact on the economy.
Speaking to Bloomberg TV, Hammond said: “The truth is we’ve got poorer. We’ve got poorer because of Brexit, we’ve got poorer because of Covid, we’ve got poorer because of the changed energy economy in the world, the higher price of the energy we consume.
“And that has to be reflected in reduced living standards and the transmission mechanism for those external shocks into the domestic economy is inflation.”
Hammond - who was chancellor between 2016 and 2019 and an MP for 22 years - backed Remain in the Brexit referendum.
His comments come after the International Monetary Fund forecast last month that the UK economy will perform worse than every other major country in 2023.
Even Russia - hit by swingeing economic sanctions by the global community due to its invasion of Ukraine - will out-perform Britain, the IMF said.
In its latest World Economic Outlook update, which was released on the third anniversary of Brexit, the IMF predicted the UK economy will shrink by 0.6% this year, compared to its October prediction that it would grow by 0.3%.
By contrast, every other country in the G7 group of advanced nations will see their economy grow - with America’s set to expand by 1.4%.
Russia’s economy will grow by 0.3% over the next 12 months, the IMF said.
Among the other G7 nations, the IMF’s 2023 predictions show growth, 0.1% in Germany, 0.7% in France, 0.6% in Italy, 1.8% in Japan and 1.5% in Canada.
China’s economy will grow by 5.2%, the IMF said, with India’s expanding by 6.1%.
Overall, the IMF said the global economy will grow by 2.9%.