Facebook Inc. is to hire 800 new staff in London, expanding its U.K. headquarters despite coming under increasing scrutiny from the country's lawmakers. The new hires -- predominately in engineering roles and to be recruited over the next year -- will bring the number of staff working for Facebook in the U.K. to 2,300. The social media company will also offer space in its new office to U.K.-based startups as part of an accelerator program, the company said Monday.