The FTSE 100 index of major company shares in London has posted its biggest quarterly fall for more than 30 years amid the coronavirus crisis.

The FTSE 100 plunged by 25% in the three months to the end of March — the biggest quarterly fall since the aftermath of Black Monday in October 1987.

“This is the calm before the storm,” wrote Mazen Issa, a strategist at TD Securities, in a note to clients.

“Economic data this week will capture the early stages of a collapse.

“That, alongside no earnings guidance could spell trouble for risk assets.”

The UK’s “midcap” stocks recorded their worst quarterly decline ever.

Sun Global Investments CEO Mihir Kapadia said: “We still have long months of battle as the US has just started dealing with it.

“Global economic growth and trade will continue to be affected until the disease is contained across the world.

“But as China shows, there is hope at the end of the tunnel.”

Financial analysts are struggling to agree on the extent of the damage to the British economy.

Vicky Redwood, senior economic adviser at consultancy Capital Economics, said: ““It may well take a few years to get back to where we were and even longer for some economies.”