Around 20 British banks and financial firms will undergo a major round of cyber warfare simulations in a bid to test their resilience against hacking attacks.
The Bank of England (BoE) is set to oversee the exercise, like it has done before, say media reports.
The Financial Times said that Andrew Gracie, director of the UK's special resolution unit within the BoE, will oversee the operation to test the resilience of Britain's biggest financials to cyber-attacks.
The exercise is the latest in a long line of now-routine cyber warfare simulations to find weak spots in corporate anti-hacking processes and systems.
Thousands of staff from various banks and other financial firms will take part in the exercise as a war game scenario is played out.
The BoE, the Treasury and the Financial Conduct Authority oversaw the drill alongside government agencies.
The exercise was tipped to be co-ordinated from a single hall where top authorities will assemble to monitor the cyber war game.
The real-time simulations are expected to test the investment banks' infrastructure performance when it comes under attack.
In November last year, around the same amount of London-based financials braced to battle a simulated cyber-attack in one of the largest exercises of its kind, dubbed as Waking Shark II.
Meanwhile, according to a new study, 60% of IT staff do not tell their bosses about security risks until it has become a matter of urgency.
More than half of IT staff said they will only inform managers when the threat is "serious", and will also try to filter out negative results, according to a report by US cyber expert Dr Larry Ponemon, who surveyed almost 600 individuals working in various sectors of IT.