Web giant Yahoo has defied one of the internet's defining characteristics by banning workers from working remotely.

CEO Marissa Mayer has ordered employees to make their way to the company's offices, as the hi-tech firm fights for its future in the face of stiff competition from search and email rivals such as Google.

Employees at the web giant have reportedly been handed an ultimatum in a confidential email: From June, be at your desk - or resign.

But in move typical of the web, that email was promptly leaked online to allthingsd.com - a technology and business website.

In the leaked memo, Yahoo's human resources boss Jackie Reses, under orders from Mayer, moaned: "Speed and quality are often sacrificed when we work from home.

"We need to be one Yahoo! And that starts with physically being together.

"To become the absolute best place to work, communication and collaboration will be important so we need to be working side-by-side. That is why it is critical that we are all present in our offices.

"Some of the best decisions and insights come from hallway and cafeteria discussions, meeting new people, and impromptu team meetings."

According to reports, Mayer devised the policy change after gazing down from her executive office in mounting anger at the office car park - which was reportedly as slow to fill in the morning as it was swift to empty at 5pm sharp, every day.

Opinion on the change was divided. One staff critic branded it "outrageous and a morale killer".

A female worker complained by email to allthingsd.com: "When a working mother is standing behind this you know we are a long way from a culture that will honour the thankless sacrifices that women too often make."

But one advocate of the change on Twitter said: "Marissa is doing what good leaders do. Making sure her Yahoo team is communicating & working together."

Some office experts believe that working together in one space can spark a workforce's creativity and create new collaborations which drive innovation, something that Yahoo has struggled with in the face of competition from Google and Facebook.

Facebook does not have office attendance written in stone as a condition of employment. Google's chief financial officer Patrick Pichette said working face to face is "magical".

It is not clear whether Yahoo's new directive will apply to the London office, in Shaftesbury Avenue.

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