James Comey, the former FBI director, is planning to confirm reports that President Donald Trump pressured him to drop his investigation into Michael Flynn’s ties to Russia when he gives public testimony to Congress, according to CNN.

A source said Mr Comey could appear before the Senate Intelligence Committee as early as next week.

His evidence may provide an explosive turning point in a drama that has been simmering for months as the Trump administration has struggled to shrug off lingering allegations of its ties to Moscow.