British cyber incidents classed as "highly significant" have risen by 50% over a year ago, the head of the country's National Cyber Security Centre (NCSC) will say on Tuesday.

A series of cyberattacks in recent months has knocked some of Britain's biggest brands, including Marks & Spencer, Co-op and Jaguar Land Rover (JLR), offline.

"Every leader, whether you're one person at your kitchen table  or the boss of thousands of people,  you must have a plan to defend against criminal cyberattacks," NCSC CEO Richard Horne is due to say at the launch of its annual review in London.