Goldman Sachs is betting on a “Boris boom” and a surge of foreign fund flows into Britain if the election delivers a clear outcome, propelling faster economic growth through the early 2020s than in the struggling eurozone.

The US investment bank expects a “Brexit Breakthrough” and a catch-up surge in undervalued UK assets as one of its top seven trade ideas for 2020, advising clients to take the plunge on sterling and beaten-down equities in the domestic sector.

“We have identified more than $150bn (£116bn) of UK inflows that could be unlocked by some progress towards Brexit resolution. The upcoming election will reset the Parliamentary arithmetic and potentially clear the way,” it said.

Goldman Sachs is closely watched by investors as the voice of global political finance. While coy about UK domestic politics, the bank's optimistic scenario is implicitly-linked to a decisive Tory victory.

It expects the UK economy to roar back to life next year as pent-up investment kicks in – “back-loaded acceleration” in City argot – lifting growth to a 2.4pc rate by the second half of next year. “Conditional on Brexit clarity and fiscal stimulus, our economists now look for annualised growth of 2.0pc in 2021 and 2.1pc in 2022,” it said.

This is a remarkably optimistic picture three years out given the potential pitfalls ahead as the UK negotiates trade terms with the EU. Such performance would be double the pace of Germany and far surpass the eurozone as a whole. It would alter the global narrative over the economics of Brexit.