GCHQ tipped-off security services in the US about alleged meetings between Donald Trump’s presidential campaign team and potential Russian spies, it has been claimed.

A source close to UK intelligence said that the listening post had become aware at the end of 2015 of possible “interactions” and that this information was then sent across the Atlantic.

Separately, Sir Richard Dearlove, the former British spy chief, suggested that Mr Trump may have borrowed money from Russia in the wake of the 2008 financial crisis.

The former head of MI6 said that potential deals to keep Mr Trump’s property empire afloat may still “linger”.