Microsoft employees have signed a letter calling on executives to ditch a proposed bid for a US military contract that would see the technology giant providing computer power for artificial intelligence to be used in warfare for the next ten years.

The letter accuses of Microsoft of betraying its principles "in exchange for short-term profits" in a plan that would force employees to build a product who have no idea "whether our work is being used to aid profiling, surveillance, or killing".

"Many Microsoft employees don’t believe that what we build should be used for waging war.

"When we decided to work at Microsoft, we were doing so in the hopes of 'empowering every person on the planet to achieve more,' not with the intent of ending lives and enhancing lethality," the letter continued.

Little is known about what the government plan to use the proposed cloud system, named the Joint Enterprise Defense Infrastructure (JEDI).

At an industry conference to discuss JEDI, the US Defence Department's chief management officer John Gibson revealed that the controversial program was “truly about increasing the lethality of our department”.

Google said it has pulled out of the bidding war, claiming it could not be sure it would not conflict with its AI principles. The company faced internal revolt for its participation in the US military's MAVEN program.