It means the UK’s overall debt is now around 99.5 per cent of gross domestic product (GDP), which is a measure of the size of the economy – a level not seen since 1962.
The pound could see a “severe downside shock if there is no deal by Christmas”.
The research comes at a crucial time as policy makers weigh up how pay for the coronavirus pandemic.
The British Chambers of Commerce (BCC) warned over a difficult year-end for the economy, with the December 31 Brexit deadline also looming large.
“There won’t be a ‘pause’ in how much rent, mortgages, food and transport costs.
“The models would suggest that the effects of a WTO no-deal trade agreement are longer term."
"Our governments have programmed the global tax system to prioritise the desires of the wealthiest corporations and individuals over the needs of everybody else."
The European rebound was the largest increase since statistics started in 1995.
Experts at the body said the initial sharp economic rebound was also being hurt by rising unemployment and stress on corporate balance sheets.