On 16 September 2012, it was reported that Prime Minister David Cameron had sacked Larry from the post of Chief Mouser, in favour of Chancellor George Osborne's tabby, Freya, as the new Chief Mouser to patrol Numbers 10, 11, and 12. Some sources described the new arrangement as a "job share" to avoid any hurt feelings.[18] Chief Mousers in the past have overlapped, or been phased in - though the position can and has remained vacant for extended periods of time. Larry is the only Chief Mouser listed on the official web site for Number 10.
http://en.wikipedia.org/wiki/Chief_Mouser_to_the_Cabinet_Office
also:
http://www.number10.gov.uk/history-and-tour/larry-the-cat-chief-mouser-to-the-cabinet-office/
Look at Larry on duty here !