Regardless of what outcome the United Kingdom and European Union reach on Brexit, the decision to leave has inflicted unprecedented damage on the former’s financial services industry, according to the founder of one of the world’s largest financial advisory organisations.

deVere Group founder and chief executive, Nigel Green, warned that the actual process of leaving the EU was “increasingly irrelevant” and that firms across the sector had already had to take precautionary action to safeguard their business.

Such steps could involve relocating parts of their business or key staff to countries within the EU or setting up legal entities in the EU. Green warned that the extent this had occurred was unknown, as many of the moves hadn’t been disclosed.

Green slammed “years of uncertainty and a lack of firm leadership from all parties” following the decision to leave as a cause, warning that low confidence in financial services would hit jobs and the Government’s tax base.

“With no meaningful access to the EU’s single market, the UK’s financial services sector is bracing itself for what is likely to be a long and steady decline, ultimately losing its coveted ranking as the world’s top financial centre,” the deVere Group CEO said.

“The steady drain of investment, talent and activity away from UK financial services might be able to be stopped, the situation might be recoverable, but confidence needs rebuilding fast.”

The financial services sector currently contributed around 6.5 per cent of the UK’s GDP.