As figures from the Office for National Statistics show, government borrowing exploded in 2020 as the finiancial toll of dealing with the coronavirus took hold. Up until the pandemic really hit the country in the spring, cumulative public sector net borrowing was on a similar level to 2019. As this infographic shows though the divergence since has been massive, and the effects continue to be felt at the start of 2021.
Adding context, the ONS notes: "The extra funding required to support government coronavirus schemes combined with reduced cash receipts and a fall in gross domestic product have all helped push public sector net debt as a ratio of GDP to levels last seen in the early 1960s. Public sector net debt (excluding public sector banks) at the end of January 2021 was equivalent to 97.9% of GDP."